Insect repellent, sun screen, and the stuff that stops the itch from insect bites.
Do those things the other campers are recommending you do to keep yourself comfortable and safe, to keep things convenient. If you don't act on their advice, then don't complain when you're uncomfortable, unsafe, finding things inconvenient.
Whether it's a modern shower house, a pit toilet, or the campsite itself, leave it in at least as good a shape as you found it.
Many campground don't have paper towels in the bathrooms. Maybe electric hand dryers and maybe not. Bring soap and a towel with when you visit the bathrooms. I also bring a couple paper towels to clean up and wipe up after myself after my morning wash up.
If you use paper towels, crush them into tight balls after use so they don't fill up the trash cans so quickly.
Don't be a know it all. If you're not sure about something, ask.