Brooklyn Mechanic?

I'm brand new to the forum. The question I have is similar to the person from California; however, I live in Brooklyn, NY. Mine is a 2013 Prius with only 40K miles. Obviously, I don't drive it much, but when I do, it runs great and I'm still getting ~50mpg. The only mechanics I've ever used are at the dealership (this is my 2nd Prius) and like others have mentioned, they want to do really expensive 'fixes' whenever I take it in. My question: Is it okay to use a non-dealer mechanic, and what questions should I ask of a mechanic to make sure they know what they're doing?