how much experience do i need?

Sitting around "planning to" do it isn't really worth a hill of beans. Ain't nothing to it, but to do it.

Get used to listening for people to talk about getting a new phone/laptop/microwave/whatever and ask for the old one. Collect cans and take them to you local scrapyards to get a little insight into how they work. When you are walking around your neighborhood, keep an eye out for what is being put on the curb, you'll be surprised what you find once you train yourself to look for it.