Besides workers for your space, you may be required to furnish the street fair with volunteers for security, clean-up, etc. If you don't comply with volunteer quotas you may not be invited back. This can seem daunting, but it's not as bad as it sounds. It's a good project for spouses and SOs. You may end up alone and be unable to take a meal break.
Fairs usually prohibit glass containers, so bring juice or pop in plastic bottles.
Cover from the sun is highly recommended, so get a canopy or tent. Make them comfortable and homey by using an India print cover, for example. Bring a plant or a vase of flowers, too. You'll be there for hours. Lamps for evening use.