Smiley,
One more suggestion, since this will be your first trailer. When you take delivery, whoever sells it to you will probably demonstrate how to take it down and set it up. When they do, be sure you have both the manufacturer's check list and pad and pencil (or your laptop.) Some of the other check lists that have been posted on this site may be helpful as well.
Be sure you understand how the sequence works, and what may or may not be on the list that you will want to consider. Every trailer has its little tricks and traps, and it's easier if you have the "hows and whys" on paper before you start. Make note of each and every step, and the sequence, no matter how obvious it may appear. Also, each person who demonstrates the trailer may have some of their own techniques or helpful hints incorporated into their procedures. If they do something different, be sure you understand why.
Once you think you're ready to go, hook up to the trailer to your tow vehicle and pull it into a quiet corner of the lot and go through the entire process yourself without any help from salesman or prior owner. Put out the leveling blocks, extend the awning, hook up the electricity and gas, just as you would your first time out. I'm always amazed at the questions that arise and how much we can miss when we're doing it alone, even after going through it with somebody else.
Then, if it's practical to do so, go spend a night at a campground within a few miles of where you bought the trailer. Use the stove, heater, terlit and other systems, just so you know what you know and don't know. Again, you will be amazed what you can learn in just one night. And, if there's a question or problem, you can shuttle back to the seller for help.
We keep a camping checklist on an excel spreadsheet, subcategorized by areas and individual responsibility. Some of our subheadings are:
Planning: Routes, Destinations, Itenerary, Reservations, etc.
Campground guides and other reference information
Tow Vehicle:
Maintenance, mechanical, tires, oil change, etc.
Contents and security
Paperwork--registration, current insurance, etc.
Trailer:
Mechanical
Contents
Expendables--propane, etc.
Furnishings
Systems
Paperwork and dealer directory
Dining and Food Prep
Menu planning for at least some of the meals
Inventory
Bedding & Linens
Toileting
Audio, video, cameras etc.
Medical Dental supplies, cards, etc.
Campsite equipment and supplies
Activities and equipment.
Reading and communications
Other documentation as necessary
Each of these has a number of line items that correspond to our current need and equipment, so we have some historical reference and basis for trying to get out of town. Even so, I'm pretty sure Walmart stock goes up every year when we leave town due to the increased sales they anticipate while we're on the road.