Porn contains: butt, point of view, pawg, twerk on dick, riding, stepsister, step sister caught, doggystyle, my hot step sister, caught, reverse cowgirl.
Porn contains: big cock, butt, big boobs, standing doggystyle, cum in mouth, fit girl, perfect ass, real amateur, real couple, hard and rough sex, close up, messy cumshot.
I'm sure it's better to search for porn with tags rather than categories. Usually authors specify a few general categories and lots and lots of qualifying tags. Here's a list of the most popular amateur porn tags. Not enough? Below is a link to all the tags used on Hobby.porn.