Hi Lenora,
She's lovely! Before you sent out on your first trip there are some things you need to be sure you have - maybe they came with the rig but if not here's a small list:
Water hoses - at least two 25' ones - I was glad I had a spare when I was at a CG where one 25' was just a couple feet short. You can get flat ones that wind up and don't kink and are very easy to store - I got mine at Wal Mart. Get spare washers for the hoses too.
If your rig has a sewer washer get a seperate inexpensive hose to use for that purpose only, and disposable gloves to wear when dumping.
A water pressure regulator - which screws onto the water hose at the end you connect to the water supply (CG faucet) It's another inepensive item that you could save you a lot of grief.
A water filter that screws into the hose and takes sediment and other stuff out of the water before it enters your tanks.
Spare sewer hose and the right connectors if you need to hook them together - test it out to make sure it hooks up before you need to use it. A sewer hose support- some campgrounds require them.
Holding tank treatment for your black tank - there are lots - doesn't much matter which kind - pick one and follow the directions.
A heavy duty extension cord for outdoor use - in case your electrical hook up cord doesn't reach. And adaptors so you can plug into any amp outlet (Laura posted pictures) - get one of each type it's not worth having your trip botched by not having the right one.
Spare Fuses in all the sizes your rig uses to be able to replace them if and when you have to.
Spare light bulbs to fit any lights that don't take standrd bulbs (most likely all of them).
Leveler blocks (they look like legos) which are great for tweaking the leveling of the rig.
Levels - to check if the rig is level front to back and side to side - you can get stick on ones inexpensively at Wal Mart. I mounted one on the A/C unit for side to side as it is right in the middle of the rig and one over the refrigerator as it also in the middle for front to back. Your rig needs to be level for the proper operation of your refrigerator. Otherwise it can be damaged if run for a period of time off level.
A fire extingisher - or make sure the one you have is current.
Chocks for the wheels - although these may not be as essential for a MH as they are for a trailer it's good insurance, especially when changing a tire.
It's also a good idea to have a lug wrench that fits the lugs on your rig - even if you have someone else change a tire - they may or may not have the right wrench if the lugs are different from the usual (trailer lugs are!).
I also carry a reasonable complete tool box, screwdrivers, pliers, hammer, hacksaw, axe, shovel etc. and small sledge hammer for driving dog tie out stake into the ground. Plus dog tie out. And don't forget duct tape and WD-40 you can fix almost anything with those two things.
Happy camping!