Any specific issue? Lot to cover without knowing what you’ve already discovered. As with all diesels, turn the key to on and wait for the “Waite to start” light to go out. For leveling, I almost always press and hold the auto level button. Once you hear the pump start, you can release. I usually dump the air before leveling. Once level, I run the slides out. Order doesn’t matter. I have to have the key on to level but not for the slides. I’d put the refer in auto mode and let it switch as necessary. As for holding tanks, keep closed until ready to dump. Black first, flush the slinky with the gray.
2006 Gulf Stream Friendship G7
350 Cat, Crusier Lift w/ Honda VTX
Blue Ox and 2019 Chevy Blazer RS AWD V6