Welcome to the forum and to the 311BHS. We have a 2017 Reflection 311BHS and love it. We usually have 8-9 with us when we camp locally (within 200 miles) and a couple of years ago (seems like it was just last year...) we traveled from Austin, TX to Moab UT, then from Moab to Park City, then to Tropic UT and back.
I started towing the 311BHS with a Chevy 2500 Diesel but after about a year I switched to a Chevy 3500HD diesel dual rear wheels. It made a ton of difference in towing.
There's not very many of us 311BHS members who post on the forum. Several post on the Facebook.com/Grand Design 311BHS page. However I think the information that you get here is far superior to the Facebook group (sorry if that offends).
Just a few hints:
Get a Valterra twist on sewer waste valve. For some reason when you open the main drain (even after a proper flushing) you get about a half gallon of junk out of the pipe,
Get a small 3 foot drinking water hose and a 90degree elbow to connect to the intake city water system. Run the hose through to hole in the tray, attach a water filter to that and run the drinking water host to the campground connection. Connect the 90 degree to the Nautilus (keeps from having scrape knuckles).
Get a good water pressure regulator (I have a Hourleey)
Get another 3 foot standard hose to attach to the black water flush outlet again run it through the hole in the tray. Keeps the tray from filling up with "dirty water"
Get a expandable standard water hose to use for the black water flush
Get a couple of clear sewer tank rinsers (one for each sewer drain)
Get a rhino-flex "Y" connector. This allows you to hook up both sewer hoses to the campsite waste dump.
Plenty of sewer hoses and connectors.
I took a 25 foot fresh water hose and cut it into a 10 foot and 15 foot lengths (use the brass connectors from Lowe's or Home Depot). This keeps you from having 25 foot of water hose when you only need 10 or so. A lot of our buddies have switched to the ZERO-G fresh water hose. Don't forget to get a splitter for the campground water. One side hooked up to the drinking water hose, water filter and then into the fresh water connection. The other has the standard hose hooked up for rinsing spills, etc.
Several plastic containers for the fresh water stuff and black water stuff (do not put fresh water with black water).
A 50amp to 30 amp dog bone and a 30amp to 15amp dog bone.
And most of all remember WalMart and Amazon is your dearest friend while stocking the camper.
Don't hesitate to reach out with any questions, the folks here will be more than happy to help.