FWIW......Been attending since 2014 as an attendee, presenter and vendor. I actually really enjoy these things but, have observed/learned a few things.
1) Be patient. As it starts to get rolling there will be a ton of people. Lines will get long. Food/drinks stands can be expensive and will get crowded and potentially run out. Be prepared with your own grub and drinks.
2) Explore and be friendly. If you've ever been to a major sporting event (have to park miles away, pass all the tailgators, pay $27.00 for a beer and hotdog and have fans from all over the world....) Then thats what to expect at an OE.
3) Weather. Check the weather. prepare for the weather. Don't believe the weather.........We've been through snow, rain, hurricane winds, tornado warnings and hail.......all, with a weather forecast for sun.
4) Take advantage of the free evening events. Many have free food, drinks and music not to mention interesting people from around the world. So, get out of your comfort zone, put on that khaki shirt, shorts and pith helmet and make some new friends.
5) As a Vendor just a friendly reminder, were all not Walmarts with unlimited inventory in the back of the store. Many have driven across the country to display and sell their limited goods. If you see something, you might consider buying it (again, not to be self serving) because due to the limited inventory it most likely will be gone when you return later for it. ( also, watch out for the BS knock-off gear). Also, remember many Vendors are there to educate you and answer your questions on their product and may not have any inventory to sell.
6) Dogs and kids are welcomed. Keep both close and under control. Nothing worse then a panicky parent looking for their lost dog or a child biting another child......
7) Bikes, e- bikes, mopeds, mini bikes, monkey bikes, motorcycles, scooters, etc. all seemed to have there place and purpose in and around the event. BUT, slow the heck down, look both ways, use common courtesy and common sense in a crowd of 20,000 people. Nothing worse then seeing an e-biker t-bone crowd of people at one of the major intersections.
8) And, just like your Scout Leader yelled at you...water, water and more water. And, your mom....sunscreen, sunscreen and more sunscreen. Flagstaff is pretty close to the sun so it can be sunny, dry and hot.
Cheers and see you there!