We have a Flagstaff 228d. Not the same camper but should be similar.
We were told to:
Level the camper side to side
Chock wheels and unhook from tow vehicle
Level front to back
Put down stabilizers
Now that you have a leveled foundation,
Raise the roof
Pull out the dinette canvas so the bunks don't snag it!
Pull out the bunks
Pull out the slide
The bunks rest on the slide out dinette, so it is the first thing in when closing the camper and the last thing out when opening. Always make sure your canvases are clear when sliding anything in or out or you may be repairing your canvases.
It is MUCH easier to pull out the bunks and put in the door when everything is square and stabile. Found that one out the hard way
Hope this helps
Happy camping and God bless