Learning Cloud computing, which service is for me?

So my development background has been backend C++ for the last 10 years, so I like to think I'm pretty proficient in coding but I have almost 0 experience in Cloud or container style projects.

In an attempt to learn and do a cool project I came up with an idea to have some kind of distributed gaming experience.

The idea is thus, my friends can go to my website and using HTML5 gamepad API be able to use their gamepads to send their gamepad state to a server. The server can take the avg of all these states to create an "avg" state of the controller which will then be sent to the game.

The first pass is obviously going to have the game be on my own local computer so I'll need some way for the html page to talk to the server, and for the server to send the gamepad state to my local computer.

I'm very new to Cloud and AWS so I just kinda need an idea of what kind of AWS services I should use to build this thing. (Also note, because I'm learning I'm still using the free tier)

Note: To also learn about web development, it would be cool if my friends have to login to my website to be able to send their controller state, so some kind of credentials would be nice to have.