You must have a valid Canadian passport for all trips outside Canada. A passport is the only reliable and universally accepted identification document, and it proves that you have a right to return to Canada. Your passport must be valid one month beyond your departure date from Cuba. Passport applications can be made on line at http://www.voyage.gc.ca/, or picked up at a Canada Post Office.
It's a good idea to visit a health care professional or clinic six to eight weeks before you travel. Hepatitis A and B shots may be recommended, and you should be sure that your regular inoculations (e.g., tetanus, diphtheria, polio, and measles) are up to date.