Going to Guantanamo City, Cuba? I trust that this is a pleasure trip...so here's some suggestions:
This area is the hottest and driest in all of Cuba, so you'll want to look for air-conditioned buildings. This is not a very touristy place, but you can mix with the locals and get into some fun partying and dancing at the clubs. They all have live music and lots of people eager to teach you how to dance. It's fun.
Ask around for someone to take you to the point where you can view the U.S. Base. There's restricted access, but there may be an insider who can get you a look.
The beaches on the South coast aren't nice and sandy, but the water is still great. The beauty of the coastline is different than Varadero, Guardalavaca, etc. on the North coast. The shoreline is generally rougher and sometimes just little smooth pebbles instead of sand.
Cuba is great...where ever it is that you go. Travel the whole country, if you have the chance! And don't be worried about the people...they're very friendly.