Largest island in the Caribbean, there are alot of gems.
Like @MikelArteta said Havana is sick, they shoot the cannons into the sea from the fortress. Malecón is nice to drive down.
Topes de collantes has a lot of beautiful greenery, I think there's one of the national parks there. When I went, me and my boy did some cliff diving and excursions - make sure you do it. I think
Cienfuegos is a dope town to visit, again very historical, if you like history Cuba's the place to be. Especially since there's still people alive who lived through the revolution, they have stories.
Trinidad has a lot of history and architecture from colonial times, it's worth seeing it. If you see end up in that town where they made a statue for that slave catching dog, make sure you spit on it
From what my girls cousin told me, the food/supply storages is even bigger, don't forget to bring something to give the cleaning staff and people you know.
When I went down I had a blue jays shirt I was wearing and the security guard wanted it. On my last day I gave it to him dude started to cry.
But yeah hit up your dollar store and buy like razors, shaving cream, tampons, deodorant etc. they will treat you like a king for that. Even used clothing I gave away most of the clothes I brought down and my sandals etc.
I remember I did 7 days and after a few i was bored as hell in varadero then went to havana and was damn wish I booked hhere instead