Welcome to the forum from Indiana and congrats on the upgrade! You should have many pleasant memories ahead.
Handling your holding tanks is not really hard but here are a couple of tips. Before you use your black tank, be sure to put some water in it. Some suggest putting about a third of a tank to start with. The idea is to have enough water in the bottom so that when you flush down the solids they do not clump on the bottom and form a concrete pyramid.
As you use the gray tank, remember that you are not at home. If you are not careful you can easily fill up your gray tank in a couple of days. Take navy showers (wet down, turn off water, soap up, turn on water to rinse) and use minimal water for washing hands and dishes. If you are staying at a campsite for an extended period of time, do some of those tasks at the shower house. After a couple of trips you will get a feel of how long your gray tank will last.
Always wipe down your dishes before you wash them. You want to keep as many solids as possible out of the gray tank. For short trips you can use paper plates, but for very long trips, you have to keep buying the silly things.
When you dump the tanks, hook up your sewer hose and dump the black first then the gray. That will clean out your hose.
If you camp at a place with sewer hookups, do not leave the black valve open to the sewer. If you do you will get that pile of solids below the toilet that won't come out. Let the black tank fill up (or nearly so) and dump periodically. Follow with a gray dump to clean out the hose.
Good luck and remember that there are many ways to accomplish the same thing so don't worry about "getting it right." As you use your camper and have questions, this is a great forum for information.
Ron and Elizabeth
2014 Rockwood 8285-IKWS
2006 Ford F250 6.0 Diesel 4x4