I'll chime in again, and won't hold it against you that you're a girl....:B:B:B.
Please note all those big smileys.....:W
Make sure you also post your rig...year, make, model, length etc. The more info you provide the easier it is to give you answers that match what you're looking for. Is this the 90 you were looking at?
Since you seem to be intelligent and willing to tackle new stuff, here's my advice.
1. Get yourself an electrical tester. Home Depot or Lowe's sells middle of the road stuff but it'll be good enough for you to use and keep in your toolbox. Two testers you should have in your box...one is a continuity tester for 12VDC and the other is a tester for 120VAC. Ask for a 120VAC Voltage tester. It will come with two flexible leads and a meter. Klein makes one at a reasonable price around $20 bucks. Any of the sales clerks at HD will help you pick the right ones and should be able to give you a quick lesson on using it.
2. With AC electricity remember this rule....Green is ALWAYS Ground. White is ALWAYS neutral and any other color is HOT.
3. To begin your search, start with the easy stuff first. Turn OFF all your lights and stuff in the coach. Start your generator. Begin turning on 120VAC appliances such as your microwave. Does it work? If yes, try other items. If not, go to #4 below.
4. Leave the generator running. Go to the 30 amp receptacle in your picture and using your 120VAC tester insert one of the probes in the top round hole...this is your ground. Next, insert the other probe into the slot on the LEFT side of the receptacle. This is your 120VAC HOT. The tester should read 120VAC. If it does, remove the probe from the ground, (round hole) and insert it into the other slot on the right side...this is the neutral. Again, the tester should show 120VAC. You cannot get shocked doing these tests.
Once you've completed these couple tests, come back and give us your results and we can move forward from there.....electricity is relatively easy to work with as long as you respect it and know the general basics. I learned long ago electricity and plumbing are like cats and dogs....water, (cats) go where it wants to go, electricity, (dogs) go where you tell it to go.....:B....Dennis
P.S. Figure about $200 labor to test your coach and about the same for materials and labor to wire in a cord, depending on what part of the country you're in. We are in Alabama at the moment or I'd do it for you for free, except for the price of materials.....good luck...Dennis