Greetings! The first place I would immediately direct you towards is the excellent (and ever-expanding!) AH Booklist here. It has a considerable number of entry-level books and online resources for general history, as well as more specific works for regions and periods you might be interested in. Below however, are a quintet of history books which should get you to a "high-schoolers" level of knowledge on this beautiful field of study, and possibly even spark an interest for even further reading down the line:

1. Everything You Need to Ace World History in One Big Fat Notebook: The Complete Middle School Study Guide by Workman Publishing (2016; ISBN 978-0761160946): This book is definitely not a great resource for any 'serious' in-depth studies of history, since the title quite literally outlines that it is meant for a specific target audience of youths and people who are still going through middle school. Rather surprisingly however, the book is an engaging, well-illustrated and decent overview of all the major "pop" periods of history (Middle Ages, Ancient Times, Renaissance, and so forth). This book is by no means going to be a great place to continue your study of history, but it is a great place to start nonetheless.
2. A Little History of the World by Ernst H. Gombrich (2008; ISBN 978-0300143324): Consider this the "bedtime story lesson" of the three books. Gombrich wrote the first edition a fairly long time ago (1936), but since then it has been updated to cover the last half of the 20th century by other historians. The book reads like a very engaging, calming, and almost soothing bedtime story, except the main difference is that everything it covers actually happened in the past. Gombrich's writing style quite literally takes you on a journey with him through the centuries of human history, and at no point does the book make you feel lost in the grand ocean of the past. If I had to recommend a singly book out of the three on this comment, it would be this one.
3. The Silk Roads: A New History of the World by Peter Frankopan (2017; ISBN 978-1101912379): This third book on the list was one of the first "semi-complete history" books I've read, and it is a rather interesting one. Out of the four books on this comment, this one is certainly the most "historical" in the sense that it is explicitly written with a purpose and a historical narrative weaved throughout the chapters. Frankopan's overarching "theme" is to challenge the notion that the "West" has always been the focus of technological, social, political, and economic developments over the centuries, and asserts instead that the "East" (a term he himself is rather skeptical of) has held the high lofts we often associate with Europe and North America in history readings. There are a few factual errors here and there, but his source work is rather decent nonetheless and provides an interesting (if lengthy) book.
4. To Hell and Back: Europe, 1914-1949 by Ian Kershaw (2015; ISBN 978-0713990898): From the seminal tragedy of the First World War to the global armageddon of the Second World War and the tumultuous years in between, Kershaw's entry-level overview of Europe's first 50 or so years of the 20th century is a fairly concise work which takes in the "scenery" of the continent without spending too much time on one particular nation. Kershaw gives particular attention to various sociopolitical trends of the early 20th century, from the demise of empires to the rise of superpowers, and the dual threats posed by communism and fascism to the continent. Each chapter contains "portraits" of various countries at the time and he does a good job tying every development back to the larger picture.
5. Roller-Coaster: Europe, 1950-2017 by Ian Kershaw (2018; ISBN 978-0241187166) This "second half" if you will of Kershaw's narrative of Europe since the beginning of the Cold War to 2017 is a great work as well. Kershaw's focus on the political developments is also set against the backdrop of social developments, cultural shifts, and even an economic overview of the 60 or so years covered in the book. If you can pick up To Hell and Back alongside Roller-Coaster, you've got on your hands a fairly good duo of books to start reading up on the past century of upheavals, triumphs, and tragedies which have (and in some cases continue) the shape the world in which we live.

These are of course, history books which deal specifically with regions and periods of the past rather than discussing the actual practice of History itself. For reading recommendations on works which cover the philosophy of history and its practices as a discipline, here is a thread with various other links which may help. Feel free to pm me as well for any clarification on the works in this list (or even more specific reading recommendations), and hope all this helps!