Disclaimer: This is a very broad question so I can only speak very generally. There will be many, many exceptions to what I'm about to say once we start talking about specific times, places, armies, cultures, etc.

Generally, they weren't made all at once.

There are shortcuts you can take when you want/need large quantities of usable weapons produced in a short amount of time but when you're making things by hand, you can only go so far.

In many cases, armories and stocks of weapons largely existed before the outbreak of war. These would have been built up steadily throughout the years. And of course, hand me downs are plenty useful. A well made spear, axe, or sword will last decades with the proper care and will generally still be just as useful.

But you may be surprised at how productive pre-industrial smiths were, or just industries in general.

For example, the idea of a production line certainly existed for many, many centuries before the industrial revolution. The simplest parts of smithing can be safely left to the apprentices and least experienced smiths while the best guys work on the trickier and harder parts, with more speed and accuracy.

And for things like swords or armor, where there is a lot of down time or otherwise waiting involved in the process, you can make good on time by making batches of weapons.

Of course, this kind of mass production assumes a lot of things, such as steady supply of raw material to work with, proper tools, adequately skilled craftsmen (which is a lot more than just the black smiths), etc.

But even a single blacksmith alone could make several tang spear heads a day or a sword blade every two days.

And of course, there was casting.

This involves pouring metal into a mold and letting it cool into the desired shape. If one has the techniques and material to create molds as well as heat up the working material into liquid form to be able to be poured into molds, this is a quick way to create lots of weapons in a short amount of time.

The problem is that you can only reliably do this with bronze and steel, since cast iron is very brittle. And of course, casting weapons can lead to issues in quality when mass producing.

But you can theoretically make as many weapons as you have molds and material.

Specifics about procurement are difficult to talk about in broad terms because they were both decentralized and centralized and everywhere in between throughout time and space.

Sometimes manufacture of weapons was concentrated in strategic centers.

Other times procurement was made simpler by the fact that each lord/commander/sergeant/leader only had to provide arms for his immediate underlings/vassals

And sometimes, men were simply required to buy/bring/make their own gear.

So to rephrase your question are you asking how you would equip your army before going to battle? If so what time and period as it varies from time to time.