Your grey and black tanks will fill quickly with 5 on board. If you have a sewer connection and can dump not an issue. If not, plan to use shower houses and restrooms as much as possible.
What a grand adventure ahead. I agree - note things that worked well for you and what you wish the trailer had to be more livable for you. Pay attention to function and comfort, sleeping arrangements, storage needs and privacy or lack there in.
I have many great memories starting in tents to towables and am now on 20+ years of Motorhome travel. Grand life and wonderful memorie. May you have a wonderful trip and begin your own memories!!!