How to make a Geo based Classified App?

Hello, I am completely new to this. I want to make a Geo based classified app, where a user can post an advertisement for help. And another user, can respond back. I can sketch the app, and code it in Xcode. But what else do I need. Is this even feasible for someone who knows only a little about coding?

I want to make an app like craigslist, but a community based platform. Where a user can ask for help, for ex.

Hello, I am in need for some dog food. Or a bowl of chipotle, or anything genuine.

Someone can respond back, and help if it suits them.

So, how do I begin. I have some ideas on the MVP features, but not sure how to move forward. Any help will be appreciated.