The most important thing is to have a good time. Immersion classes are designed to give you daily living language skills. Use the afternoons to practice your new language doing what you like to do. Shop at stores using as much of the language as you can. Visit the museums and sites nearby.
Most schools offer optional trips and events.
Take advantage of these and attend as many as possible, as they are designed to introduce you to local culture and give you a great opportunity to learn new vocabulary and practice speaking. Most of all, become a local by patronizing the businesses near your lodgings. After the first three days, the bartender at the local wine bar began instructing me on the various Spanish wines while other patrons joined in. Your new neighbors and family will become a key ingredient to learning more than a language. You will learn a lifestyle.