afdds,
I am no expert but I can give you a couple of driving tips. Others with years more experience will likely chime in too.
The 5th wheel being hitched over the axle versus at the bumper like your Alpenlite travel trailer - will have a different pivot point. Also the length and the axle placement may be different. All of this means that the 5th wheel will not track the tow vehicle in the same way as the travel trailer. So there is a little bit of tail-swing and the tail will not be turning at the same rate as the truck.
So my advice is:
1. When turning right out of a campground, tight parking lot etc., do not hug the right side curb. If you can, have your rig straight and have it over the center line a little. Then, when you pull out, wait until traffic is clear in both directions of travel. Pull straight ahead and cross into the other lane of travel a bit, if safe to do so, then begin cutting the tires to the right. At the same time, watch your mirrors to watch your right side trailer wheels and tail as you move through the turn, then fully into your own lane.
Trust me on the above! With my previous RV, I was all the way right, in my own lane, pulling out of a campground. Thought I was doing well by pulling straight ahead, well out into the road and over the center line. But, because I was too close to the right side of the lane, when I cut the wheels to the right and pulled into my lane of travel, I scraped the entire side of the RV with a stop sign
Fortunately, it buffed out. Except for the scratch all the way across one large window
2. You are right about the tail swing. This is due to axle placement. And axle placement is due to balancing the load of the RV to ensure a 20-25% pin weight. Just leave several feet of room on the opposite side you are turning to ensure you don't grab the side of a building or some such with the rear cap.
That you have experience pulling an RV should give you much confidence in this new adventure. Take your time, be smart and be safe.
Jim