In order to comfortably, safely, and reliably tow a 4000+ pound TT with your truck, you should have the following:
Heavy Duty Transmission cooler (usually part of HD towing or trailering equipment packages). If you are unsure, consult your window sticker if you have it or the Ram dealer. Towing anything high waled takes a lot of power. This means the transmission is shifting a lot in order to keep the engine in it's power making range, which is very much different than unloaded. Every shift means extra heat.
A brake controller. I highly recommend a proportional one such as Tekonsha's Prodigy line (P2/P3). Their cost is reasonable at $120-150. Installation and adjustment are simple. Braking performance is smooth and strong when needed.
Your truck requires a WDH to tow anything over 500 pounds of TW. That's about 4000 pounds loaded and 3200-3500 pounds dry. So you will likely need one and holes will also likely be drilled into the trailer's A-frame. I recommend one with integrated sway control. They tend to cost about $500 compared to $300 for standard. Owners that have had both report noticeable improvements. Learn how to adjust the WDH you end up buying.
If you have the above and towed the proposed Avenger model, I estimate your truck will be 500 pounds over GCWR, GVWR, and tow rating as well as over rear axle. I do not expect a comfortable experience with that combination due to the soft suspension. Performance may also not be acceptable. That V8 is weak and the transmission and axle gears will not help it.
Your questions show lack of experience. That's fine we all have to start somewhere. I do not recommend starting out with first RV towing overloaded.
My Advice: Rent a similar TT similar for a week/weekend. Gain some experience. Or sell the truck, use the cash from equity to buy a used TT. Buy a more capable truck. Any 2011+ 3/4 ton would make towing most TTs as effortless as possible allowing you to enjoy the drive and camping experience.