They have a magnificant aquarium in Tampa and Channelside is right next store, which is a collection of restaurants, shops, and nightclubs. They often have live bands in the center area.
You can take the trolley to Ybor City, but that is more 20something oriented these days. But they do have shops, restaurants, and nightclubs, cigar making places, etc.
The zoo, Lowery Park is nice. The beaches in Clearwater, St Pete, Indian Rocks are very nice. Lots to do there - Dolphin sight seeing, water side places to eat, jet skis, etc.