Good vehicle for teenage parents?

Cici • Mama and Etsy shop owner! My etsy shop is SerenadeBaby
We are on a tight budget, I am still in highschool while my boyfriend is graduated already. We have a son and quite a long commute to work until we move (about 30 minutes). We want something that's reliable safe. Of course we are going to buy used, but what are good types of cars to look for? 🙂