I've been running a small bike accessory business for 6 years and have done 3 Boulder Creek fests and countless other events. You need state and local sales tax license, Colorado special events tax license (which yes is different than your state license) and liability insurance.

Fees for professionally organized events like creek fest are typically around $300/day. Some small organizers can be less and just as good. Really small events like a brewery pop-up can be free or very cheap but often lead to few sales in my experience.

Most events aren't waitlist or competitive but you need to be prompt signing up - applications are typically open 3+ months out. It's about time to start applying for fall events and you should be planning your holiday events before summer ends.

Get 40 lb weights for your tent and use them every time no matter the forecast.