This is embarrassing. I know I can wire the first length with an extension cord but I have no idea what to use if I want to add more to the same circuit. I don't want to use something that can't handle the amount of electricity or something like that. Obviously I am not very knowledgeable in this area...

My rack will have 8 levels of 2 foot. Do they sell a type of wire that will work for it at a hardware store? I don't want to have them all individually wired. Thanks.