You don't need to volunteer to entertain kids in a hospital. Veterans hospitals are filled with guys whove given service to their country and would be happy to have the diversion of a live show. Be flexible as you may be working on a ward with guys in beds or in a day room with guys in pajamas and bathrobes and limited mobility.
Of course, youre doing it to get experience performing for a live audience, but you should show up practiced in the individual tricks and well-rehearsed in doing them all together. One of the major failings of amateurs in putting an act together is that they fail to rehearse the entire act, plotting out how they pick up things, where props go, etc. Keeping something timed to, say, 30 minutes, and not beyond, is good. Leave them wanting more.