I mean budget determines a lot. On the low end, if you're in el zonte no need for a car. However it's possible to rent for the day informally from the shop where the first bitcoin payment was accepted. I recommend eating at Vikingo when they are open and making a reservation. You can get transport from the airport, I have a driver friend that we've relied on dm me.
In Uvita I'd say get a car. Restaurants are great and don't miss Dominical, especially the Indian restaurant there it's 🔥