Reddit mentions of Paper Diffraction Glasses for Lights, Festivals, Raves (Assorted Neon, 50 Pairs)

Sorry for the delayed response, but I've been quite busy with school!

Never have I heard of the cup of tea supplies haha. Very unique, but I can totally get behind it. My hand warmer is also a lighter! And as for my fan, I carry a handheld folding fan with me at all times :-)

Things on me or in my fanny pack for quick access:

Lighter when someone wishes to start a fire. I carry regular BIC lighters. Gum when someone wants some gum to chew on. Always carry two kinds, juicy and minty. My go-to are Original Juicy Fruit and Extra Winterfresh. Lollipops when someone wants a lollipop. You cannot go wrong with Dum Dums since they're tasty and relatively small / not as much of a commitment as larger lollipops. Folding Fan when someone needs a breeze of fresh air. Vicks VapoRub this stuff is magic and you shouldn't ever leave to a rave or festival without it. Seriously, some next level stuff. Put a dab under your nose if the smell of cigarettes is getting to you, or if you just need something nice to smell. It will change your life. I also like to apply it to my folding fan (people love it). Small Spray Bottle when it gets hot and someone needs a mist of water. I typically add 20-30 drops of clary sage-scented essential oil to a 10 oz. bottle for extra sensory fun. Fun to spray in crowds, too, but beware, as there are a select few who don't necessarily like this. Chapstick when someone's lips are chapped. This is the most important thing I carry! Phone when someone needs to orient themselves in the right direction using the festival app to head toward the next stage. Also nice to have your schedule on your phone.

Things in my bookbag for random access:

Earphones when someone is having a bad time, you can pull them to a quieter place and play some soothing jazz or ambient tunes for them. Portable Speaker when the music stops, you can keep it going and start a little party. Extra Ear Plugs when the music gets too loud, you can offer these around (people will love you for this). Sunscreen when it's unbearably hot and you need to protect your skin. Mini Hand-Sanitizer when someone needs to clean their hands (or other body parts). Baby Wipes when someone needs to use the restroom. Bubble Gun when you're feeling extra and want to bring joy to unsuspecting people. Also, everyone loves bubbles. Extra Bubble Liquid when you're all out of bubbles but wish to make more bubbles. Fun things to hand out when you see someone who's not in a good mood, or if you just want to give someone something. I've been carrying small rubber ducks which squeak when squeezed, and colorful plastic mini slinkys. Glow in the dark aliens are also cool to have. These things also relieve anxiety or mitigate uncomfortable come-ups, I've been told. Space Blanket when the people get cold. Battery-Powered LED Lights when you need something to brighten up the mood. Incense/sage leaves when it stanks and you want it to smell a little nicer. Also fun to look at the smoke dance. Essential Oils when it really stanks and you want it to smell a lot nicer. Also fun to rub on yourself or your belongings and temporarily become the greatest smelling thing to walk the Earth. Balloons when you're waiting around at a stage and want to start a balloon party. Also great to hold on to / place your lips on when the bass is kickin'. Glow-Sticks cause why not?
Disposable Diffraction Glasses when you want to spread the joy of color. Candy when people want some candy. My go-to are Rainbow Nerds. Extra gum when the gum runs out (rare, but it does happen). Extra lollipops when the lollipops run out (rare, but it does happen). Xans when someone is having a pretty rough time. Joint when someone wants to smoke. Spare Party-Favors when someone loses theirs. Whether it's tabs or molly beans, this always happens, so it's best to be prepared and have their backs when mistakes are made. Wallet/Money when you need to buy (or sell) something. It's important to keep this safe and keeping it in an obscure pocket in my bookbag is the safest way I know of doing so.

That's all I can think of for now, but I'm almost positive I've covered it all. It sounds like a lot, but many of these items are relatively small and fit inside any typical book bag pretty nicely. With more restrictions on the types of bags they're allowing into music events, I may leave out the fun things like the bubble gun, slinkys, rubber ducks, glow sticks, and balloons, as much as it makes my heart sad, haha. But yeah, hopefully you can get some ideas from this :-)