Nobody is going to be able to give you a walkthrough in a post. There are a lot of concepts at play which are all going to require you get on google and start learning. You’ll inevitably run into issues that can be specifically asked about and answered but this is so general how would we even begin to give a walkthrough.
If I had to give a spot to start I’d say look into interacting with the apis (or any apis in general) first in your desired language and then figure out some things you can do with the data you’re getting back from the calls.
This sounds like a fun project to be honest. Are there any risks involved by getting bad content through federation that’s out of your control?
Just a week or so ago I read an article about a guy running a tor exit node personally and being held responsible for the traffic