Re: 1st Trip?
Yes, to level the trailer, you need something you can drive one side up onto. Some people use a set of wood blocks (cheap) and others use a set of interlocking plastic blocks (light weight and 'cleaner'). You will want to be able to select any height between 1 inch and 4 to 6 inches, in increments of no more than 1". Any jacks that are on the trailer are either for leveling front to back, or stabilization. To level, you look at your level guage on the trailer and get an estimate of how much you are off side to side, build a 'hill' that high, and pull the trailer up onto the hill. Verify you are now level side to side. If not, drive off the hill and add to it/subtract from it. I don't know how to level a TT front to back, but on a fifth wheel, you use the front landing legs. Once you are level in both axis, you can lower any stabilization jacks until they just start to 'lift' the trailer.
You will also need chocks to keep your trailer from moving (or rolling off the 'hill'
) These can be simple things which go in front of/behind the wheels, or fancy dingusses which clamp between the wheels of dual axel rigs.
A rug which wraps around the entry step is a good way to help keep the interior clean. If you have an awning, a 'deflapper' kit is useful to reduce 'flapping' in the wind. Make sure you have any tools which should have come with the unit to open/close the awning(s).
Hook up supplies - 15/30/50 amp converters, extension cord for your amperage, Electrical test guage (to insure the hookup you are about to make will not damage your RV), Surge Suppressor, White (anything else may not be suitable for drinking water) hoses for water (25' and 10' are the most useful, I also carry a 4' which comes in handy at times). A WATER PRESSURE REGULATOR (I didn't use one once and blew the pressure sensor on my water pump and the toilet supply line). An inline water filter (to keep sediment and such out of the tank; I use one which is rated against bacteria). A 'Y' adapter with individual shutoffs (the cheapest you can get (Home Depot?), so you can leave it behind without remorse). Spare hose washers. If you have an external fresh water fill port, a special nozzle with shutoff valve (from Camping World). I find the brass 45 degree and 90 degree adapters to come in handy at times. For dumping the tanks, a clear adapter, 90 degrees, 45 degrees or straight as appropriate, hose (the RhinoFlex kit seems the best currently available), dump site adapter, some way to flush out the tanks, plastic gloves and or disinfectant. If you have cable TV hookup, some cable for that, with male and female adapters.
Basic tool set, including a 'RV' screwdriver (they use funny screws on those things, clutch, square, etc). In particular, any tools you need to manually extend/retract any slides. A ceramic heater and a 12v fan for auxillary heating/cooling.
Toilet paper, and the black tank chemicals you like.
As you gain experiance, you will come up with the complete list for your RV and your camping style. For instance, if you visit friends a lot, there are several more hookup items which can come in handy.