Recommendations/Advice for New Turtle

Hello, I would like to get a turtle. I've never kept reptiles, so need some help. My daughter (11) will be helping take care it. We want something that is small, terrestrial, and easy to care for. What species would meet those requirements. What sort of habitat would we need (I have unused 20 and 50 gallon fish tanks), substrate, shelter, heatlamp? How do they interact with humans? What is their life expectancy? Thanks!