Linking Database of Android App to World

I'm fairly new to the world of Computer Science, and I have questions that I am not sure where/how to look for an answer for them, otherwise I would have just googled. So, I made an app in android, and it has a SQLite database. Right now, I am the only one who uses this app, it's not even published...the app is like any other social network website where you post something, and others comment on it. So right now, I'm the only one who posts and comments, and the results are all saved in SQLite database in my phone. How can I "publish" my database to the world? So other people could access the database too? add comments to it etc. when they have the app installed on their device.

What topics of computer science I need to learn to go with this? I'm sure there's a simple answer to this, but I don't know where/what to look for. If there are any links to websites, or similar questions on here that could help please post it here.