Game Options In-game

I’m making a Space Sim, and I need an options menu where you can change different aspects of the game (For example: Difficulty, AI count, sound settings, etc.) There’s probably no specific script to do things like that, but if there is, and you don’t mind posting it, that would be great, (btw, I’m not asking for you to write any scripts for me). Even better would be if you could lead me to some sort of documentation, so I could learn it myself. Thanks in advance.