Well in the 16th and 17th century in the Netherlands humor was very crude. A lot had to do with shitting, farting and pissing. So a lot like the potty humor of kids.

My proffessor in the University of Leuven once wrote a book about it. (it's in dutch)

Verberckmoes, J. (1998). Schertsen, schimpen en schateren: geschiedenis van het lachen in de Zuidelijke Nederlanden, zestiende en zeventiende eeuw. Nijmegen: SUN.

the title means; lauching and gigling: History of laughing in the Southern Netherlands in the 16th and 17th century.

edit: The book has a lot of jokes people told to their friends, and almost all of them where about sex or relieving themselves.

It's been a couple of years since i read it so I can't tell you a lot more.

I don't really have information on how comedy evolved, but a lot of the comedy was in the form of poems, a specific form being the Fabliau. You can see from reading that the comedy was quite bawdy at the time. There was also satire and that is best shown in the Roman de Fauvel which took aim at the medieval church. Im English the most famous poet was Chaucer, who I'm sure you remember from high school. A good example of comedy just beyond the Middle Ages is François Rabelais who was a Renaissance humanist and wrote during the 16th century. His work was extremely bawdy, and his most famous work is Gargantua and Pantagruel. and to give you an idea of how dirty here is a bit from the description on Wikipedia.

text is written in an amusing, extravagant, and satirical vein, and features much crudity, scatological humor, and violence (lists of explicit or vulgar insults fill several chapters).

Hopefully someone with more experience will be able to come in and give you a better idea of how the humor evolved throughout the Middle Ages, but hopefully this gives you a general idea of what humor in the Middle Ages looked like.

In Italy there was a partially improvised form of comedy called commedia dell'arte. It was a healthy mixture of crude jokes, satire, and slapstick. The actors wore masks and performed outside. The best troupes had wealthy noble patrons. Having performed commedia and other mask work, I gotta say, it's exhausting.