New bloke, a GA aircraft would need a big honkin' load of fuel to get from Canada to Cuba without a stop in the US. Best route would be a stop at NAS, which is only 200 miles from MIA; Bahamas and most other Caribean states have no restrictions on flights to/from Cuba. One other snag would be citizenship-
AFAIK Americans can travel to Cuba but it's illegal for them to spend any money there.