Help me decide what car to buy please

Hey y'all-I'm looking to buy my first car this summer, but I know absolutely nothing about cars and was looking for pointers on what I should look for, maybe brands that I should look at, anything you can think of that might help!

My budget is around ~20,000. Ideally, I would like all wheel drive-I'm in the northeast and snow is a little brutal. Looking at sedans or smaller SUVs (I like the look of the Subaru Crosstrek.)

What companies are reliable? What should I be looking for in an engine? How many miles should I be looking to keep a used car purchase under?

Thank you so much for any help you can give me!