How would I approach the development of this game

Hello guys, I am nee to unity. I have been coding in javascript and making servers and websites but this is my first time with c#.

So I want to make a game which will have the following features:
1. Login / register
2. Capture user progress through out the game and send it to server
3. Save the state of game and always be sync with the server in terms of information and data

So I would like to know the general architecture that I should use and how should I approach the development of this.

Thank you.

 

Google Firebase looks good for you