Does your community have a festival? When is it? What happens at your festival? Have you been part of a group doing something in the festival? A festival will attract a lot of people. Any activity you decide to do will create some interest. You will even find many people after the festival asking you what you did and how it went.
Schools have even designed and built floats to go into their festivals. You could make banners and go into a parade. Design and look after a stall or display. Use well-known songs and write new lyrics that a group of you can perform. Conduct a short play or street theatre performance. If there is a procession, organise a mass of students to display placards.