Here's the suggested materials list from Code.org:
What materials and supplies are required for CS Discoveries?
Normal classroom supplies (pens, pencils, coloring, scissors, extra paper)
Worksheet Printing (There are worksheets with some lessons. Some teachers get around this by doing everything digitally.)
Couple Decks of Cards
Containers that can hold water
I'd also add poster paper, markers specifically for coloring, tape, and Post-It notes (for brainstorming or think-pair-share discussions).
If you want to totally splurge, I'd go for pre-cut sheets of aluminum foil for the first lesson, these sticky poster pads, and you gotta have a couple decks of these playing cards. At a minimum, you want one deck of cards for every 8 kids in the class, but a couple more wouldn't hurt either. The only thing I've found useful is some kind of system for managing the various activity guides. If you go the paper route, you might find yourself with a lot of printouts to keep organized.
Hope that helps!