So, say I'm a peasant in the early years of the Hundred Years War, and I don't make enough money to afford my own spear, if my lord called to war, would he provide me with a spear, or would I be going to battle with just my fists?
Neither. You wouldn't go to war without a weapon of your own. Contrary to popular folklore, medieval armies weren't made up of peasant farmers armed with farming implements but by semi-professional soldiers who provided their own weapons and armour. Here is a link to what most of the english army would have looked like by u/WARitter. Here is another link that addresses army conscription in the middle ages by u/TheGreenReaper7.
Sorry about the short post but I have an exam in a few hours and can't expand much right now. If you have any questions I'll answer them when I get back tonight.