New financial adventure

Looking for, I guess "frugal" advice, mostly just financial and knowledgeable input for an unfamiliar situation. I would like to put some money towards a car, and not just some car off Craigslist (which I've done twice before and had good luck with). I want this purchase to be a reliable worry free vehicle for me and my 3yr old to commute in. It is just the 2 of us, so I have been looking at Subaru Impreza(5door) and the Outback, also Rav4 and CR-v. I would say I have decent credit at most, not entirely sure where it stands, but I do have a student loan debt that is deferred for another year. Is it best to pay the debt all off then pay cash for a ~20k car, or try to finance with a practically unknown/unestablished credit. Any advice on cars and finances is appreciated.