My StarCraft Travel Star 18SD is about 30' long. The front 8ish feet of that is toy deck. So it is rear heavy. The unloaded weight is about 4500 lbs, with a tongue weight of a bit over 500 lbs. Loaded with gear, and ready to go, I'm probably around 6000 lbs, and 600 or so on the tongue. I tow with a big block powered 2500HD. The trailer itself barely puts the rear down onto the factory overloads. So I can get away without using a WD hitch. However, the weight causes the front to porpoise, and it drives me crazy. So I use the WD hitch for that reason.
I recently removed as much lap sealant (caulking) as possible from the roof, and replaced it with Eternabond. I'm hoping it lasts longer, and eliminates the need for constant re-sealing.
As far as winterization goes, I flush the water system with RV anti-freeze, fill the pipes with RV anti-freeze, and dump a bit down the drains as well. I then open up the water heater, and leave the drain plug out. My buddy uses an attachment, and his air compressor to simply blow all of the water out of the system. I may try that this year instead.
I found a cover last year on KSL, (it's similar to Craigslist) which was made for a 21 foot trailer. It worked perfectly to cover the living quarters portion of my trailer.
Other than that, watch the tires, keep the batteries charged, and go have fun. I am new to ownership as well. Although I bought the trailer from a buddy, and have been borrowing it at least once a year since 2012.
Jeff