I started a nonprofit in 2012 with two missions: to provide free, hot meals to responders and the community in the event of a disaster, (I was a few months behind OBR, but same concept. My folks responded to Joplin and fed those in need. We are a big supporter of OBR.) and to help raise money for other 501(c)(3) organizations. I, and my volunteers, donate our time and equipment. We exchange BBQ for donations, and after recovering the cost of the raw ingredients, give most of the proceeds to the other organization.
If you are looking to make money, this probably isn't the venture. If you're looking to help others, it's very rewarding. Work with the organizer of the event. But be aware of your local health code and laws. Our first year, we had to get a Temporary Food Permit (in VA) for each event. Last year, Virginia amended the health code to exempt 501(c)(3) organizations, like they do schools, churches, and fire departments.