You bought the wrong radio. Because it is a H.A.M.s radio, it likely will not be able to transmit on GMRS frequencies.
IF it does transmit on GMRS, or IF you can get it unlocked, it is going to take multiple semi-complicated steps to program a repeater.. Good luck.
..you really did buy the wrong radio... UNLESS you bought the GMRS version, in which case if you did, you dont need to enter any frequenices - just pick the repeater channel, enter the TX tone, and talk..