What things do you look for/check when shopping for a used car?

I'm going out with my daughter to look at a car for her. She's an adult, she's buying it, I'm just along mostly for moral support. Doing the dad thing. However, it's out of my wheelhouse, and I want to make sure we don't miss anything.

What sort of things to you look for or check when shopping for a used car?

Do you have any suggestions?