Attendance at Events and Conferences

There are many well-attended events in my area, a major one coming up Sept. 27& 28 here in Carmel (11th Annual Carmel International Arts Festival). I'd like to set up a booth or table and pass out basic info., maybe more. Any recommendations?

In April, "Fiesta" takes place over 10 days in San Antonio at numerous venues and with attendance over 1 million.

Do I produce my own flag, bunting, or banner; fliers and handouts. Does anyone oversee such things or do we do what we want to do? (See where this can lead?)

How do I approach the event organizers; as a "member," "organizer," or what?
What credentials do I have to offer if asked for such?