As others have mentioned, go through everything, even if you are a seasoned boater. Ask them to show you the following (partial list, not all inclusive):
1. Bimini: Proper way to open and close, while it is open - look for tears in bimini, loose screws (give it a shake), how to put in trailering position, top speed with it open, etc.
2. Engine: Break in, process/sequence to starting, what do the alarms/beeps mean, what fuel to use, winterizing, prop, What to do if it doesn't start or the beeps/warnings are different than normal, etc..
3. Seats/Upholstery: Look at seams for tears/poor stitching, ask about proper maintenance of material, how to get various stains out such as sunscreen, food/beverage, blood, pollen, etc.
4. Go through the entire helm and have them show you what each of the switches do. Verify they do what they are supposed to. Go through the radio and how to sync Bluetooth or any other features. Go through the SIMRAD or whatever screens you may have.
5. Batteries: Where are they? Any switches? Any special maintenance needed?
6. Trailer: Maintenance of trailer, method or tips on how to launch/load pontoon on trailer, tie down straps, tow with cover on or off, etc.
7. Overall: Look for scratches, bents, dings, and anything that doesn't look right. Point it out, make sure they note it. Depending on when you get your boat, they can always work on minor or cosmetic issues at the end of the boating season (unless you are lucky and have boating season all year). You may get a small list of items during the first summer that may need to be looked at or repaired. Best for them to do everything at once.
8. Safety: Lanyard kill switch for ignition, ask your dealer about laws specific to your state, etc.
Go through the entire boat. If you don't know how to do something or what something is, ask. Take notes if possible. You will be going through a lot of information and with the excitement, I guarantee you won't remember some of the minor but important details.