Advice on Affordable Used Cars?

I live in the Miami area but willing to search up to Broward. I don't have a specific preference other than I'm a big 6'4 guy and want to comfortably fit on something that's spacious but not huge. Priorities are economical, good performance, not a gas guzzler, etc.

I could use any advice on what kind of make/models, years, and resources to look at that will get me a good deal. Facebook Marketplace, Carmax? Something else? The more info the better.