Best helper: just expiriement with stuff.
Put yourself a goal (for example, creating a hero reviving system), then try making it.
If you failed, try again ! if you succeeded, create yourself a new goal.
You must know about variables, however, to make a lot (lot lot lot lot) of things.
If you don't know what variables are... learn a bit in school and come back ^^
If you do know but you don't know where to create them - go to the trigger editor, now click on that yellow X and thats the Variable Editor for you.