The Cuban people are warm and friendly.   In the area near the port most of the people have some form of basic English, but not as much as in other Caribbean islands.  Most tour guides have a good knowledge of English, but at times may stumble for a word or too.  It is not necessary to speak or understand Spanish to visit, but you may find it handy to know some basic Spanish.  Some signage especially around the port have signs in both languages.