Congrats on the new trailer! We are a couple years into our first one and still loving it. Keep a notebook and pen handy to write down all the things you forget. I kept a journal for a week in the house of what things I used on a daily basis and then just added in "camp fire, fishing and plumbing" items as well. I will say our first trip was 4 hours away, but we were only 20 minutes from a Fred Meyer and Walmart, so some of the not so critical things we forgot were easy to purchase.
Enjoy your adventures this summer!