You are going to need a bullet level. Use it in the reefer to level the TT. Remember the scissor jacks are stabilizers, not levelers; don't try to level the TT with them. Level left to right with boards under one side (if necessary), chock the wheels, then unhitch, then level front to rear. You will want just the slightest tilt to the back corner so the air conditioning condensate drains off without dripping on you as you step out the door.
Hook up city water and make sure it works throughout. Bleed the air out of the lines and out of the water heater. Then connect your shore power.
You can hook your stinky slinky up if you like, but leave the valves closed until ready to break camp or the tanks are full, whichever occurs first. You'll want some nitrile gloves when it comes time to drain and flush the tanks. Remember, black first, flush it, then grey.
Wal-Mart has a travel section for such things as soap and shampoo. My job keeps me in hotels a lot, so I collect all the little bottles of stuff plus soaps they give out. Same kind of thing.
Raid the fast food places for ketchup, mustard, mayonnaise, salt, and pepper. Those little packets do not have to be refrigerated and can store in a zip lock bag.
Take some small diameter nylon rope. You can use it for clothes lines, tie downs for table cloths, or a belt. ;) Clothes pins are handy to have too.
A 110V extension cord, about 15 feet long.
Check the bathroom door. If it locks from the inside, bring a small screwdriver to unlock it from the outside.
Since it's a new experience all around, some LED nightlights might come in handy. One in the bathroom, another in the living/kids room.
Finally, sit down with your owner's manual and read the section on towing. Really work through it step by step and don't assume anything. Your family's safety depends on you to really understand what you are dealing with.
Do you have a WD/SC hitch? If not, you really need to look into getting one.
Be careful, but leave room for fun.
