Here are some websites that offer a dizzying amount of supplies, both traditional and unconventional. Take a look!
Amazon

Bachelorette sunglasses, funny mugshot signs, flashing ring toys, drinking straws, necklace whistles, and catchy banners — Amazon really is the digital marketplace for everything you can think of… and even what you can’t imagine.
Etsy

You can find everything on Etsy, especially if you’re into handmade party supplies, like custom-shaped sugar cookies, hippie bride sweatshirts, and funky glasses to brand your bridesmaids’ team.
Urban Outfitters

From the Fun + Games section, to its rich selection of pool floats, UO really has everything to make your party an absolute success. You will find a hub of hidden gems in the “novelty gifts and toys” section, too!
Minted
Minted is the wonderland for every paper goods lover. It is packed with customizable design offers for invitations, place cards, wedding signs, menus, thank you cards, you name it.

Ban.do
As soon as you land on ban.do, you start getting excited about life in general. It has a funky-chic feeling that can inspire you to create a themed party that screams style and you. It has colorful string lights, heart-shaped pool floats, confetti tumblers, and the like.
Other Party Supplies Websites to Check Out
Additional sources of inspiration can be websites like World Market, eBay, Grove Collaborative, BHLDN, Lovehoney, and Lulus. Some advice? All these websites have various limited time offers, so if you have enough time to plan your party, you might even be lucky to catch a discount!