Being a Spanish colony from the 15th century until the Spanish-American War of 1898, it is no surprise that Cuban Spanish, sometimes referred to as Cubano, is the lingua franca of Cuba – spoken by 11 million native speakers. Despite its isolation, the Cuban language has been influenced by the vibrant diversity of the population.
However, you will find that most if not everyone in your hotel will speak English and outside of your hotels in the bigger cities you will find that lots of people will be able to communicate in English. You should have no problem getting by if you only speak English or pidgin Spanish.