I don't really think you could accomplish this goal the way you're describing it, though you could learn enough to convince yourself you did. You seem to want to strip down your understanding of history to the macro-scale and metanarratives (a word historians use to describe "umbrella" interpretations that combine the respective histories of long timespans or geographic areas). But if you never qualify those big ideas by delving into more specific histories, they lose meaning very fast.

What, for example, would you consider to be an empire? Will you, for example, ignore any eastern Native American tribe that didn't band with others like the Iroquois Confederacy? Or is an "empire" here any apparently autonomous society? Will you then include all the small and secluded cultures of the South Pacific? If those are hypothetically too small, where will you draw the line between what's to be studied and what's not? Will you try to decide which of these empires "matter" or have significance, and which don't? That creates a whole host of methodological obstacles for defining your terms, not to mention pitfalls such as becoming Eurocentric, etc.

Once you've got your list of empires, you want to parse out their cultural values. But any given empire is much more than colored borders on a map. Many, many empires have/had a lot of internal diversity, meaning diverse values which can not only be contradictory but also were in direct contention with one another. Good luck understanding early modern English history by choosing to focus on just Catholic or Protestant values and not their interactions with one another.

Will you just try to isolate whichever values were apparently dominant at the time? That doesn't work either because minority influence can often be extraordinary. Slaves in the 19th century American south, despite horrific subjugation, managed to wield surprising power over their masters and the terms of their own enslavement.

What defines a major event? Major for whom, and in what ways? What determines who you consider a major historical figure, and how will you establish their significance over other candidates? Many of the answers to these questions require historians to delve very seriously into the perspectives and motives of diverse groups in any population. If you're avoiding specifics and going for the macro only, that becomes very difficult.

Look, a person could take a stab at this and ignore everything I just said. They could avoid the nitty gritty details, make quick and dirty judgments about who and what mattered, study only that stuff, and work out a functional narrative and encompasses only those elements. It could be internally consistent, and look like it works. Do you think it actually would? If it did, how would you know anyway?

Let me ask another way: if in a thousand years a historian wanted to study your life and compiled the top 50 facts about you--your dates of birth and death, your occupation(s), place(s) of residence, relatives, yearly income, and so on--they could learn a lot about you, sure. But how close would they come to understanding everything that you are?

History is a lifelong pursuit. You can always learn more about a specific subject. If you are looking for an overview, just pick one topic at a time and start reading.

To specifically answer your question, it depends on what kind of coverage your interested in. The scale that you are interested in will determine how long it will take to get a solid understanding of "all of History". Are you only interested in large empires? Maybe you only want to understand the roots of modern day powers? Maybe you want to focus on Western Civilization or the Peoples of the Pacific Islands. One of the challenges of getting a good complete overview of history is that their are so many different things going on at once, often times developing independently of each other. Personally what i do is focus on a region at a time. European History, East Asian History, African History, ect. While they are all related, it may be tough to juggle all of them at once.

I would suggest a certain way to expand your knowledge from my own personal experience; that is speak with people who study history, connected sciences and start reading a bit in the field. I asked /r/AskHistorians three years ago:

I want to read 12 history books in one year to know "all the things", what should be on the list?

This was a great experience. Reading is one of my main forms to gain knowledge and starting to read these factual books did change my perception of reality, the past and consequently the present times.

I went from I know nothing over Why the West rules for now and the Great Divergence to "so that's a basic outline of things judged important leading to our current state of affairs". I read a lot Palmer's World History and stuffs closer to my region's history Postwar and now know that there is no detail I am fully aware of, but know of some broad strokes about how historical writing is currently done.

I can only suggest starting reading books like I did, Why the West rules for now and the Great Divergence (or an article about it) where a good start for me to get a feeling about how "the most important empires" and themes came to happen - it also convinced me that the "Great Person theory" often holds little water, as humans are mostly equally able, smart and when equipped with equal tools faced with the same problems they will often come to similar or equal solutions. What way suits you may be different thought.

However nothing can substitute for a 5 year academic study of history and constant work in the field - even then you won't know all of history in the end but specialize but will be able to find the persons, books and sources which will help your understanding.

Edit
I noticed that on average I rather read 6 pages a day of these books instead of 20 (with exceptions like Why the West rules for now and the Great Divergence) because historical writing is often enormous dense and deserve some thought.

2 out of 3 books made me have this feeling of reality shifting you get from good fiction books when you notice the main plot was different all along. The Structures of Everyday Life and Memory and the Mediterranean by Braudel were nice because they made me once again realize how human people in the past were and that the world is a place of different experiences with a lot of common or shared parts.

It's a nice goal to have, and it's always good to learn history, speaking from personal bias here.

Anyway, as /u/Borimi and /u/StarkBannerlord have pointed out, there's a starting point with what definitions and how to organise '"all" of history', there's what could be called macro history and micro history as well. Macro history is probably the most common perception of the study of history, where you learn the battles/empires/large events and names of commanders/rulers/influential people etc. Whereas there's micro history, where you might look at say "the effect of 19th C Hungarian pipe smoking" or the like (which can be surprisingly interesting).

So, going on a macro history outlook, as you seem to have as your goal, it's probably best to read about larger entities (if there's records), and follow the timeline of each as they go through the "time periods" of history and what happens, which will link in with other things and what's happening. Usually with the historical recording of macro history, it's going to be hard to get things like cultural values and that sort of passing micro knowledge while focusing on a macro scale.

There's also the problem of pre-existing bias, like who has been written about and in what light they wrote about them, like, was it a scribe demonising a former ruler to make the new one look great (and keep their head), or was it to promote something that was relevant at the time etc.

So to add a bit more of a ramp to your goal, there is that factor. While I'm not saying it's impossible, I think it will be very hard, but I think the pursuit is worth it, if you enjoy history as much as you seem to from your post. So my advice is to stick with it and I think the journey will be beneficial. It's also amusing to try and find patterns (although they're not always the same) throughout history.

And yes, it's easy to fall into a Eurocentric view, with a lot of English language texts (especially older ones) being of that viewpoint, along with other stuff like Orientalism etc.

I suppose that depends on whether you're more interested in being a historian or a history hobbyist. You can learn enough of every era to beat your friends at trivia questions and have reasonably in depth discussions with an expert on the subject but you're never going to be the expert yourself. You're always going to have gaps.

Luckily the good thing about history is that you can just pick up a book or open Wikipedia and start learning about the Assyrian Empire one day and what Nepal was up to during WWI the next. Just learn what you find interesting.

I have this very very thick book that I bought as a cut-out at the bookstore for only $2: The Columbia History Of The World. So apparently the editors of that tome thought that it was possible to do what you are asking about. But the fact that I could buy it so cheaply makes me think that nobody is very interested in trying to read the whole thing (I've only read bits and pieces of it).

With all the above comments in mind, why not start with something lighthearted and easy to read like Bill Bryson's A Short History of Nearly Everything and use that as a springboard form which you can delve into more specific subjects you want to know more about.

Disclaimer: I have not read the book I'm recommending though I have read other Bill Bryson titles, but I believe its a good read the covers a lot in (very) light touch detail.