tampons at camp

Hannah
Hey everyone! I am going to be working at summer church camps a bunch this summer but I have some questions about tampons and yeast infections.
The camps have a lot of lake and water activities and I was wondering if you have to change your tampon right after getting in the water? How long can you keep it in?
Also how do yeast infections work? Can you get them after staying in a wet swim suit for too long?
How can I take care of myself as best as possible this summer??