Agree, food is pretty bad (because all they grow on the island is sugar cane and tobacco) and there's no shopping or usual consumer-based pursuits. There's not much to 'do'.
That said, I loved it.
Fabulous music, scenery, dancing, cocktails. Havana is fascinating and there are concerts and museums and art galleries. The people are kind and welcoming, the cars are cool.
There is a dual currency system, so tourists pay for everything in one currency and locals in another. As a tourist, it's quite hard to find opportunities to use local currency but there is the odd street food stand and peso bar, and we did find a wonderful bookshop which charged in local currency.
There is poverty, yes and many of the buildings are crumbling and decaying, but there is also a high quality healthcare service. Outside of all inclusives (which aren't my cup of tea, but I see why you're going for one) stay at casa particulares which are basically people's houses, but they are regularly inspected and controlled by the state and are usually nicer than the hotels.
We went to Havana, Trinidad and La Boca and Vinales for spectacular scenery.
It helps to have a bit of basic Spanish in some places, but you won't need it in the resorts. Even just knowing how to ask for a beer and where the toilet is.
Hope you have a wonderful time!