Prelaunch marketing campaign on social media platforms

We are a start-up company and working to build a unique App which is somewhat similar to food delivery Apps. Before we go live, we want to run a small Prelaunch campaign on social Media platforms : FB and Insta to check if there is a market for our concept. We are looking a freelancer social media marketers who can design and run our campaign on FB and Insta for a limited audience (preferable in Mumbai city). Objective is to validate our hypotheses and database of early interested customers as well as Chefs.