New to trailer Life ordered new Truck and TT

Congratulations on your decision to adventure out. Curious..did you order the truck and TT in matching colours? We have seen that quite a bit in rigs that are all new.

We have 250' of white hose. 200' of electrical extension. Our BBQ is a baby weber, we cook every meal on it and have a nice grill tray to cook things like eggs etc. A mat for under your awning keeps out a lot of dirt from the TT. Make sure you get a brand that does not damage the grass, well worth the extra money.
There are many things we carry such as both a well stocked tool kit and first aid kit. To level and support we have some 6 x 6 blocks as well as some planks of wood.

For leveling we have a set of these Clicky.

We always connect city water supply through a pressure regulator. We always close the valve and shut off the 12v on board water pump when we leave our rig unattended.

For tank flushing I bought one of those shrinking hoses (as seen on TV!), mainly because it fits in a small bucket and isn't like coiling up haywire. So far it is handy and has stood up well.

We like our Blueline sanitation hose/fittings from Prest-O-Fit - easy to use and compact. I'm not sure what length I've ended up with, I've dragged one or two on the road to shorten them up a bit :S
We use a clear coupler on the rv to see when the tanks are flushed. We use one of those accordion supports to grade the sani hose down to the drop when parked on a site.

Don't skid your sani dump hoses around on the pavement and concrete when they are full of fluid - they become sprinklers :)

Barbeque - we carry a little round ball charcoal unit.

Check your tire pressures every travel morning & enjoy your new truck and trailer and retirement.

With a new TT you will likely have a black tank rinser built in to the unit. Get another general purpose hose and a Y with shutoffs for the water spiggot to be able to hook up both hoses. Do not use your fresh water hose for rinsing your tank. This also enables you to rinse your sewer hose before storing it. You should also pickup a clear fitting for your sewer connection to observe if the tank is running clear and thus empty and clean. I set up like this.....Y to the campground water spiggot first. one side gets the water filter and fresh water hose to the trailer, other side gets a anti siphon valve then the general purpose hose with a spray nozzle which is kept coiled up on the ground and I use that for various rinsing needs and tank rinsing when I dump my tank. You will be fine with your tow setup. I have a Silverado 1500 and tow about the same lbs as you and I have no problem. If you get some wiggle(not sway)in the rearend of the truck when you're towing its likely the tires. I had that problem and advice on here was to air up the tires to their capacity listed on the sidewall. That solved it.

With a new TT you will likely have a black tank rinser built in to the unit. Get another general purpose hose and a Y with shutoffs for the water spiggot to be able to hook up both hoses. Do not use your fresh water hose for rinsing your tank. This also enables you to rinse your sewer hose before storing it. You should also pickup a clear fitting for your sewer connection to observe if the tank is running clear and thus empty and clean. I set up like this.....Y to the campground water spiggot first. one side gets the water filter and fresh water hose to the trailer, other side gets a anti siphon valve then the general purpose hose with a spray nozzle which is kept coiled up on the ground and I use that for various rinsing needs and tank rinsing when I dump my tank. You will be fine with your tow setup. I have a Silverado 1500 and tow about the same lbs as you and I have no problem. If you get some wiggle(not sway)in the rearend of the truck when your towing its likely the tires. I had that problem and advice on here was to air up the tires to their capacity listed on the sidewall. That solved it.

Leveling blocks-I use pieces of wood planks
Sewer hose-I use a Rhino hose and have a full extension for it. Put one of the vinyl fence post w/gutter drawer on your DIY modification list. There are a few threads about that on RV.net.
Water supply hose-I have a white drinking water safe hose, a couple of them, IIRC. Bought it on sale at Camping world.
Pressure regulator-Yes, the Watts brand or similar with adjustment are the better ones, they allow better flow rate while regulating the pressure.
Surge suppressor-An electrical management system (EMS) is a better choice than a filter that just suppresses surge. They cost 4X as much. Some folks also have an autoformer which allows operation of appliances and devices, maintaining the correct voltage. Some of this choice will revolve around where you hook up and how often.
RV barbeque- Some folks like them but I have stand-alone BBQ gear so can locate where I want. Again, tied to preference.
New screen-I bought my LED/LCD at Sam's Club. It is mounted on an articulating bracket so viewing angles can be adjusted. The swing arm bracket is mounted on a piece of wood that spans three studs. The wood backer is glued to wall and screwed into the studs. You may have a location in your rig where the TV backer for a mount is already installed. There will be a sticker that says "Mount TV here" or similar.

Hope this helps and wishing you many happy miles!