The best way to engage in prompts is to start interacting with people on What are prompts?
First, note that prompts are structured by categories. See the PROMPTS section on the left menu for a list of all prompt or find them in CoMakery (the Collabathon's task management system).
Note that these prompts have different repositories, based on what they create, such as GitHub, Google documents, etc. A process was designed to submit contributions to prompts.