I purchased a lightly used 2008 Classic 25FB almost 6 months ago and I thought it was going to be problem free. I was wrong. Found lots of stuff wrong.
You should find a campground with full hookups and not worry about sight seeing yet and try to stay a few days. Test out all the systems. Take some tools with you in case you need to fix something. Take a voltmeter test any electrical problems. Take all your manuals.
Verify the converter is working properly and is charging the batteries. The propane leak detector will flash amber instead of green if the voltage drops too low. My converter wasn't working properly. I had to replace it with one from Bestconverter.com
Run the AC all day long to determine if it leaks water condensation from interior housing. Mine leaked and it appears due to a faulty caulking job where the drain tube connects to the drain pan in the overhead housing. Drop the interior housing and look at the insulation of the center of the housing. If its stained you will probably have a leak when the AC starts creating condensation.
Turn on the electric part of your water heater with the AC running to see if it blows the 30 amp breaker. If you have 50 amps run both Acs. I had to move the AC off the 30/20amp breaker to the end breaker. Too much heat generated by the AC and the 30 amp. Kept popping. I may replace that 30/20 barker.
Even though you are on full hook ups turn off the water and let the water pump provide water pressure for a day. Observe if any burping of the water pump is heard. That means a leak on the pressurized side
Run the water heater on propane. Verify it starts up and stays lit.
Take a shower and observe if any water leaks into the hallway floor from underneath the shower enclosure and framing. If you can remove a heat duct from shower wall in the bedroom you should be able to observe if the the shower drain P trap is leaking. I had leaks to the hallway and the P trap. I removed the shower door and sealed the gap between the enclosure and wood frame and caulked the plastic flashing.
With water hook ups you can test your black flush. Open the access door in the closet where the water pump is likely located to observe any leaks from the check valve. Mine was broken and it sprayed the interior behind the shower enclosure with water. It started running out where the water hook up is located on the outside. I ended up putting a male/male elbow instead of getting another check valve.
You can fill up the water tank then fill up the black and grey tanks to see if your monitor panel is working correctly. My black water tank sensor acts up sometimes to where it shows full when it's empty. I'm giving it a treatment of laundry soap and water while driving to campsites. Maybe the tank needs a good cleaning to get rid of dried up leftovers from the previous owner. Right now it seems to be working.
Play with the exterior awnings to learn how to deploy and retract them. Verify all the acorn nuts are tight. Some of mine were loose. I used blue Loctite on all the nuts on my awnings.
Have you had the brake line and brake actuator recalls performed. I insisted on these recalls being performed and insisted the Actibrake controller be replaced by a Dexter unit before signing the papers.
If your tires are from 2007 then get them replaced. Also buy a tire pressure monitoring system. I use TireTraker.
Check the pads of the stabilizer jacks. I had one of them fall off because the wing nut came loose. Also check all the bolts of the stabilizer. If like mine some will be broken off at the head. I need to get them drilled out and replacement bolts inserted.
Open and close all the windows and use silicone on rubber if stuff. Use a flat blunt old spackle knife to break the glass away if stuck to the rubber. Be gentle.
Check all interior lights. I found one that didn't work and had the dealer get me a new one and I installed it. I have another reading light where the dimmer doesn't work. I want to switch them all to LEDs eventually.
Check the oven. Bake something in it. Check the stove top.
Check the fridge for performance. Run it on electricity one day and electri the next day to see if performs equally. Verify if your Dometic fridge is part of the Dometic recall. They put baffles around the burner flame in the exterior fridge area. Helps keep the flame lit on windy day towing or when big trucks pass. Test out the microwave. Heat something for 5 or 6 minutes with the AC running. You'll have to switch your heater to propane first if you only have 30 amps.
Verify no leaks when draining water from the kitchen and bathroom sinks.
Check the radio and TV operation as well as the crank up antenna.
After you test everything then you can go out to play
It took us 6 trips to finally get to a point where nothing went wrong with our Airstream. Always found something on each trip.