Where to buy tote/hobo bag?

i need a tote or hobo bag for school. im 12 years old and i need to hold my binder, journal, my library book, and my pe clothes. im looking for a bag with a long strap that goes onto your shoulder or sometimes even across your body. i would like ones with a knitted sort of hippie design. or just something cute. nothing leather though. it can even have a knot on the strap. in stores or online please.