If you live in the Burbank area, the easiest thing to do is get your materials from Carter Sexton Artist's Materials on Laurel Canyon Blvd. The are a locally-owned small business, have our list of supplies in-stock, offer a 20% student discount, and they are now open Mon-Sat from 10-5 for in-store shopping or they will do curb-side pickup. Give them a call and tell them you need supplies for Exploring Art and they should be able to help you -- 818-763-5050.
If you prefer to order supplies, here is a materials "wish list" for Blick Art Supplies -- https://www.dickblick.com/lists/wishlist/T5A58JA8LVOJI/items/ Blick's orders usually take a while to get but I think their stores are now open for in-store or curbside pick-up.
The materials we need are listed below and they are pretty common brands/products so you can also find them on Amazon, Target, Michael's, etc. :
Pentel Oil Pastels (at least 12 colors) Watercolors (at least 8 colors)
Crayola Washable Markers (at least 8 colors but 12 is nice)
9"x12" Mixed Media Paper (watercolor paper is fine, too, but usually more expensive)
Black Fine-tip Sharpie (just a plain old Sharpie)
A good paintbrush - having a flat and round is nice