A game with (1) global score ranking (2) login feature

Hi, I am new to Unity. I plan to construct a mini-game which has a simple feature - highest score.
For highest score, I mean the player can submit his score to the server (maybe some cloud server), the player can view his position in the global ranking. Where can I start with?

In addition, I would like to publish the game in iOS and android platform. For both platform, I would like the player login to the game using Game Centre (iOS) and Google Play (Android), so that the players do not need to enter their names when they submit their score to the global rank.

Is my concept correct? Please guide me if I am wrong, many thanks!

 

You can make a simple high score server in PHP, which you would access from your game using UnityWebRequest.

As for GameCenter/Google Play, if you require login to these, then you will never see my high scores. I hate those things. Please be sure to provide a way for people to just enter their name or initials if they get a high score. (Store this entry in the PlayerPrefs, and they'll only ever need to enter it once.)

 

If you want to use the Google Play Leaderboard, here's a video I found very useful: