for switches ad variables its like this. lets say ur player walkes into a room and its too dark so he goes to the light switch so when u press the action button on the light switch a switch turns on and the light goes on. its pretty much the same for variables exept u can use 1 varibale for more than one thing like if u have a variable for a chest to unlock yu can use that one for another chest as well all u have to do is change th constant number

as for scripts i dont even no how to do those and u really dont need it that much coz u can just find them on google