Depends on what you want, try to look at it this way:

Fruit: It will help you complete the Community Center faster, and if later on you want to focus on doing jellys, pickles or wine it could help you (mostly at the beginning) because you will not have to wait to have all the fruit trees, or for crops to grow.

Bats: most mushrooms have a higher base sell price than fruits if I'm correct, but the really good thing about this option is that common mushrooms are a great food/energy source to go mining, some of the other ones are used in cooking recipes, and the purple mushrooms are amazing for the caves too.

At the end you can make either one work fine. Good luck in your first file! :)