Advices regarding AI prompt

Hi everyone, I've been able to get for free a one year subscription at perplexity. It offers to create an AI agent I can save (not sure proper wording, not English native) mainly to help me maintaining, fixing or creating some automations, dashboard items, ... To do so I need a prompt that will tell exactly how it should react but since i never really dig into AI yet, I'm looking for some guidance to set it up correctly