You can find ATMs in Cuba, but know that they don’t accept American debit or credit cards. There is a 3% withdrawal fee or credit card usage fee for most transactions.
If you’re not American, don’t take American dollars, the exchange rate will be terrible plus you have to pay an extra fee every time.
Banco de Cuba, which are proper banks, or Cadeca, which is like a currency kiosk. The bank usually gives better rates.
You need to have travel insurance to travel to Cuba. They do spot checks at Customs and if you can’t produce policy documentation, they make you buy insurance there.
When you fly to Cuba, if you can, go with cabin luggage only. We managed to and it was the best. We didn’t have to worry about losing our stuff or about it getting damaged.