How to create a FB msg chatbot? I just need some direction

I have been studying and practicing some swift, python and C programming and I am trying to venture into creating a FB messenger bot. I want to create something like a scavenger hunt through fb msg ( similar to urbanhunt.co ). So far I’ve started using the instructions laid out here https://developers.facebook.com/docs/messenger-platform/getting-started/sample-apps/original-coast-clothing but I am having a hard time figuring some of it out like how atom, node.js and heroku all communicate with fb and webhooks etc. etc. Is there anything (e.g. YouTube video(s), write-ups, books etc.) that you would recommend to point me in the right direction? or maybe even something step-by-step? or would anyone be willing to be a mentor to me in this venture?

TIA!