Music and dancing: The street music in Cuba is unbelievable. You will of course hear classic songs songs like "Guantanamera" and "Hasta Siempre," and you'll also find the very Cuban styles of bolero, son, guajira, and danzón, so brush up on some Buena Vista Social Club. For flashy cabaret, hit the Tropicana — you’ll find the low-key spots easily on your own. If you are a salsera or salsero, consider taking a casino (Cuban salsa) class, then put your skills to work at Café Cantante or another of the countless nightclubs in Havana.
Walking tours of Old Havana: These tours are bookable through hotels, which often have connections to tourism companies (or host them in-house). They're an organized and informative way to see a breathtaking ground view of Cuban art, architecture, and historical monuments, and the guides will usually tell you the best place to buy that souvenir case of cigars you will obviously bring back with you.
Other cities to visit: Cuba may be small, but there is much to see. If you're able to hit multiple cities on your trip, consider looking into Trinidad, Santiago de Cuba, Varadero and Holguin, Camagüey, Cienfuegos, Santa Clara, Bayamo, and Matanzas. The beaches are stunning and there are buses every 30 minutes from Havana that can take you to the ones located east, like Bacuranao, Mégano, Santa María, Boca Ciega, and Guanabo.