How do i script and what do i script?

I have been looking for help for a very long time and just found this website so I am asking for how to make a cool scripted game!

Thank You
 Awsomfire1234

I would suggest youtube videos

This guy is good

https://www.youtube.com/playlist?list=PLXX6hhg4CysYf0M-_GtCEOgGlkBfrXsoJ

Also read this

http://wiki.roblox.com/index.php/Cookbook

As for what you should script, just whatever you want. Almost nothing is impossible