Well I went to the G.L.A.S.S. rally last year, have a schedule conflict this year so won't be going.
I do not know about getting there early, though you should be able to find nearby parking. At the rally
You will find dealers, Not just RV dealers (Including the one I bought from) but vendors of every type, There will be folks there who sell after market add ons to improve your rig's handeling, There should be internet dealers both satellite and "internet-in-a-box" will be sold there, There will be vendors trying to sell you camp ground memberships, and cook ware, and craft items, and badges, and foods and every sort of accessory you can imagine (Think camping world) Insurance dealers, and Mac the fire guy (he sells fire extinguishers and gives seminars on fire safety.. ATTEND HIS SEMINARS, one He is a good showman, you will enjoy the show, 2: you might accidently LEARN something... I did, and I already had a bunch of training in that area (I am a retired emergency dispatcher)
There will also be, more than likely, a class in RV safety. If you attend (I took the class in California last January) make sure your insurance company finds out. DISCOUNTS result
Evenings there will be a show in the main arena It will most likely be a professional show, and well done... Prize drawings follow the show.
G.L.A.S.S. offers one or two meals a day as an option on your membership. They were decent.
Of course there are other food vendors as well
Parking, You will be nose to tail with another RV, They suggest you only use 30 amp and not over use your AC as the fairgrounds is not wired for that many Class A motor homes. But you will have power, and I think Water (not sure on water) No sewer though there is a dump station on site ((As you leave the grounds the last road to the right BEFORE you exit is where the dump station is) All in all I had a good time. The Frustrated Mistros perform in assorted locations (Just a group of members who ban together. You know, when you are singing there is NOTHING like Rehersal,,, And I suspect they have had NOTHING like Rehersal ) (A joke I often use in chruch where I'm one of the music leaders and often have Nothing like Rehersal... Yet we still pull it off cause. Well... Somebody's got to do it)
(Real fun when you find your partner is not there, the music is something you've never seen before and you are expected to lead the congeration in song)
Actually. they do practice, and are not bad considering they are mostly non professionals.
You will also meet tons of people... One thing I have in my basement is a fake campfire, It's a gas fire, From camping world (not campfire in a can) and since there is no where to have a real campfire there I set it up at night... Drew a crowd as it were (We usually had at least half a dozen folks sitting around my propane campfire) Great ice breaker
One final suggestion.. If you have Bicycles, Scooters or any way other than the venerable Addias Footmobile that is sidewalk approved... Make sure you bring it with you.. I put many miles on my bicycle that weekend.
And if you have a Damon (or other motor home that calls Elkhart Indiana home) you are perhaps 30 miles out from Elkhart