Welcome!
And hope you have a wonderful trip.
The fact that you asked about etiquette means you have about 90% of it already down pat, as you must already be a considerate person.
You don't need to tow a car. 24' isn't any sort of real or physical limitation, although longer = more care needs to be taken, especially if you're not used to driving large vehicles.
And yes, if you pull up camp during the day, it's customary to leave something marking your campsite as occupied, if it's not essentially an RV park, where your camp site registration is monitored by a host on site.
Helps keep A holes from poaching your site.
Good luck, have fun.
2016 Ram 2500, MotorOps.ca EFIlive tuned, 5โ turbo back, 6" lift on 37s
2017 Heartland Torque T29 - Sold.
Couple of Arctic Fox TCs - Sold