congrats!
you will need stuff to dump the tanks and holding tank chemicals.
don't forget a can opener! We keep it simple. 2 pots, 2 skillets, coffee maker, a set of 4 corian dishes plate, bowl and cup (Walmart), plastic drinking "glasses",
We went to the dollar store and bought storage containers and organizational trays for the bathroom cabinet and under sink storage, cheap towels and bath cloths, kitchen towels, pot holders.
Folding chairs or bag chairs for sitting outside and drinking your favorite beverage. Small BBQ Grill (we have a propane one).
If you plan on longer trips and want TV, you will need to get over the air digital TV stations or satellite (another long discussion for later). If you want access to the internet and email you will need a smart phone, tablet, laptop and either use wi-fi (we don't) or get a hotspot aka Mi-Fi. (we use Verizon).
Sheets, blankets and maybe a mattress topper unless your trailer has a good mattress!
Visit your nearest Camping World store and you will find lots of things you "need" LOL!!
Lonny & Diane
2004 Country Coach Allure 33' "Big Blue"
Towing 2008 Chev Colorado 4x4
Semper Fi