Providing Security

I've been trying to Google my way to the legislation that would cover this and I really am coming up blank. I'm looking to be pointed to the laws and regulations covering: If one were to volunteer to help out with security at a very small event in Colorado, what special requirements or laws cover this situation. Are any of the cities different? What are the regulations about being armed as well (conceled and open)?

The only thing I've seemed to be able to find has been the licensing in Denver for those being employed by a company that provides security services (Merchant Guard licensing).

If anyone can help point me in the right direction, I would appreciate it.