Before you plan your trip to Cuba it’s good to know that there is an American Financial and Economic Embargo towards Cuba. You will understand when you are in Cuba, the consequences of this embargo. There are lack of everything, the shops are empty, there is almost nothing to buy, as a tourist, except for Cigarrs, Cuban Rhum, Cuban Handcraft and Art.
Here I explain the background to embargo (Source Wikiwedia).
The United States currently imposes a commercial, economic, and financial embargo against Cuba. The United States first imposed an embargo on the sale of arms to Cuba on March 14, 1958, during the Fulgencio Batista regime. Again on October 19, 1960 (almost two years after the Cuban Revolution had led to the deposition of the Batista regime) the U.S. placed an embargo on exports to Cuba except for food and medicine after Cuba nationalized American-owned Cuban oil refineries without compensation and as a response to Cuba’s role in the Cuban missile crisis. . On February 7, 1962 the embargo was extended to include almost all exports and it still is active, almost 60 years after the Revolution.