If you google event planning or better “party rental companies”, there are several large companies that are either nationwide, or you should get websites or contact information for local caterers that are looking for temporary help. Don’t go to the job listings, because with the high turnover for summer jobs, they would probably fill positions through word of mouth.
Use this link to see the top 30 event planners around the U.S. One of them should be in your area.

Good luck!

You’re in the perfect place on earth for this type of position. Disney is always in need of servers and food help. Apply there.
And, they also do weddings.
Getting a position there would really give you a good overview and experience in the food world.
If that doesn’t work, start applying to local caterers. You can do all of your ground work in either of these job resources. It will teach you all about this world of catering. They’re just great places to start.
You might also want to consider a resort in your area. They prepare and serve food. The resources are endless. All it takes is an application.
You’ll do great.
Now, go do it!