If you like live theater, go and see a play at Manzanillo Theater. Look online for scheduling details.
This arts and culture attraction in Manzanillo is popular with travelers, so put it on your must-see list. Don't think that's all there is to do here, though. There are a lot more options waiting for you to experience after Manzanillo Theater. Museo Histórico la Demajagua, Iglesia de la Purísima Concepción, and Celia Sánchez Monument are close by.