Colorful beads https://www.amazon.com/gp/product/B007QNFQIK/ref=ox_sc_saved_title_2?smid=ATVPDKIKX0DER&psc=1

Letters/Numbers https://www.amazon.com/gp/product/B073CKKLJJ/ref=ox_sc_saved_title_1?smid=AKO24X58OJBB1&psc=1

String https://www.amazon.com/gp/product/B01LX50N4Y/ref=ox_sc_saved_title_4?smid=A3M8FB044EYZU2&psc=1

I would also suggest some white or black beads just to have some contrast with all the colors