OK i know this has been asked probably hundreds of times before, but I cannot find the answer anywhere. I want to make it so an event will need a certain number of items, not just one, to complete. I've heard of something like adding a variable to an item, but i don't seem to grasp how to do that without explanation. Sorry I couldn't find the answer on my own. =\

You just use the change variable event command and set it to the number possessed of a specific item. It's really straightforward. Then you use the variable as a conditional branch.