Yes, a lot of folks will think you are working too much. It's your gig, enjoy it.
We have done this for a few years. We did 'work' 24 hrs each at a wildlife refuge for just the site, no $ for 2 months.
It was hardly work....extremely small gift shop and a small area with animal identification info, I think we saw 20-30 people all day. We just read or used Internet. And in our free time, I did photograghy which was the reason we wanted to be there.
Some gigs you will want to do again whether you are paid $or not, others you won't. Move on.
I would say for advice, is to relax. Everyone thinks 'it should be done this way'...and get upset because it could be done more efficiently, effectively, etc. if you make a suggestion, let it go if they don't change.
Example ... We moved a small trash can at the Yellowstone store to be under the area of the coffee creamers/stirrers because people would leave them or try and throw them over to the trash can.(..and miss), but, 'no, we always leave it there'...
Your boss today might be the person who started 1 week earlier than you!
We do not serve as camp hosts. We think that would be like on duty all the time!
Where will you be for the summer?