Yolihuani is a must when visiting Calvillo, it is a hotel/ spa that has day passes and its only 25 minutes away. There is plenty to do here, relaxing messages, temazcales, hyrdromassages, they have a pool with a swim up bar, and even a restaurant, and if you'd like to spend the night their rooms are lovely.
When visiting calvillo this is one of the most common and simple things to do, walk or drive over to the plaza, enjoy the views, shop around, and you MUST have a delicious nieve from el Guayeco.
If you'd like to have a couple drinks at a bar this is a nice place that sometimes has live music.
This is another popular bar recommendation where they sell good micheladas, for other michelada spots ask the couple:)
Presa de Malpaso is in the outskirts of calvillo and sometimes it might have enough water for a boat ride and sometimes it might not lol. But there are a couple seafood restaurants that you can enjoy.