would be great to publish a game where the user could register, login and logout. subsequently to login, you load the data from the previous game. It would also be very useful to teach us to create the database and everything related to store the records.
This all is out of the scope of C2's forum (once again).
This is webdeveloppement and you can find tons of examples and dediacted websites on the internet.
But this can't really be simplified and there are a lot of things to take in account/learn. Make a search in your own language for "mysql database" or "PHP login/registering".
Find a webdevelopment website in your own language this is where you'll get all you need. But be sure to look up for infos by yourself first, and not just wait for the infos to come at you.