It is not fair to kept a wild turtle captive. It's the equivalent of locking you in jail. You should take it back to where you got it and release it. You can always buy a turt from a pet store if you want one as a pet. But be sure that you research them so that you know all that is involved in their care. The turt that you captured will likely die in captivity if you keep him so please release it as soon as possible. He may live 30 years in the wild but will probably die within a year if you keep him. Sorry to have to tell you that, but it is the truth.