How do you keep care of a box turtle?

Hey. This is Laura and Kylie. We bought a box-turtle at the reptile store today. We were getting a turtle. Welll the employee said that no one would buy the box-turtle. SO wee felt sorry for him and bought him. Just because we're 13 don't mean we can't handle a turtle!! We ask the employee questions about the turtle. THe Stupid employee knew NOTHING about the turtle. not wat stuff he ate besides turtle food and the emploee didn't know if he was a boy or a girl. Nothing. so iff you could tell us what a box-turtle ate or how to tell a boy from a girl. That would be great. thanks