I’m looking to throw a family field day event Sept 14th at this location from 9 til 4, but outside though nothing I’m looking to do will cause for renting the inside space. Would I have to provide some type of fee?

Yes, there is a fee to rent the outdoor shelter. However, if you don't need the tables, you could not rent it. But I'm not sure if the outdoor bathrooms would be open or not.

Thanks for the feedback, not looking to use the shelter but out of curiosity do you know how much

Yes you have to pay a fee for the shelter next to the playground of you will need to use it. I rented it for my daughter's graduation cookout and celebration years ago.