I need football offensive tips for being a reciever?

ok so im gonna be playing offense for my schools 8th grade team. i played defense last year as a cornerback for my first year and during track season my coach told me that for sure im gonna be a receiver next year. i could run and catch a ball only problem is the routes. can anybody help me memorize or give me something to know what like a post route is. or anything that helps me as a reciever. i dont know much about football so any tips would be very helpful. im 5.9 and about 125 pounds if that helps.