Hacking PHP Game

[SpawnCrash]

I am planning on making a PHP Hacking Simulating game, i was wondering does anyone know where i can get information such as simple ways people hack into things.

The games go up in levels so i want to know all sorts of hacking people can do and i would like to to be in difficulty.

Thanks

Passwords in comments <!--- password: 4jgr49fndn ---->

SQL injection '1=1'

Hidden directories that are unsecured because they're hidden.