Yes you can prebook everything including Spanish lessons, accommodation, transfers and so on. You can actually stay up to 3 months in Cuba on a tourist Visa. Every 28 days you have to go to an inmigration office in Havana and pay 25.00 CUC to renew your Visa. For as long as you stay for 3 months you will be fine.
Our specialists have published on this website some of the most interesting tailor made package holidays to Cuba. Feel free to browse our list of package holidays and get quotations online.