Welcome, and congratulations on your new trailer.
We use DampRid for condensation control. We use a fantastic fan for exhausting humidity from showers and cooking.
Bug stuff is important. StingEze works to relieve the itching in the spots that you forgot to spray - stuff works miracles and you can get it at Walmart.
Command hooks work for us. We have several - one for keys near the door, one for the hand towel in the kitchen and several for pictures that we hang. All are pretty lightweight items, though.
There are a lot of inexpensive places to stay. We like state and national parks and we have several local campgrounds (one owned by the county) that charge about $25/night. Then there are the free places:
freecampsites.net
Happy camping!