You bought a X rental???!!!
Congrats, our X rental was our 5th RV. And we've never been happier. Those "compact" models are very good IMO. Can fit most anywhere. CA came up with them because of so many people wanting smaller to drive in cities etc. Not to mention people abroad taking their "holiday" in what they think is a "big" vehicle.
Maybe CA is different now than 8 years ago when we got ours? But I would change all fluid, don't forget steering fluid. And change all of it, don't just suck out the fluid with a pump. Change the whole thing. Did they show you were owners manual are on-line? Our Majestic has manual awning and newer TT has elec. I'm getting used to elec, but our old manual so much better IMO. Only thing wrong with our RV is it doesn't get used enough. :)
Bit of history. Our model 23P was sent out to pasture when your model showed up. Our 23P is 24 steps long and on f-350 frame (not E frame). Basically a large camper that is only 2 step longer than my pick up.
If CA still mails another set of keys... When the other keys show up, the tag might have a "unit" number on it. Keep track of it. You might see your unit in some pic's in blogs all over the place.
Yes, first upgrade we did was a new mattress. Even though the mattress was brand new and never slept in, it was like sleeping on concrete. If you go with a locking gas cap. Saved old gas cap. Mine won't pass smog test with a locking gas cap. I have to put old style on to pass, I don't know why, vent maybe?
Happy travels