Hey @GhostGirl123 welcome! You're not alone in having a tricky time navigating the forums (it is something we're working on changing!) so feel free to ask if you need any guidance.
We got some resources that can help:
Creating your first thread
Tips & Tricks
List of Social Spaces
Tips for communicating online
And of course please feel free to come hang out in the Newbie's Social Club too!
As to your question.... whooo boy can I relate to this with every fibre of my being! I have ADHD, and the restlessness is a huuuuge part of it. It sort of feels like if I don't wriggle, I'll explode! I am not saying that feeling restless is exclusive to ADHD, quite the contrary - but it could still be worth checking it out? Largely because I've found that the medication really helps with the restlessness. If you are curious (cos I had NO IDEA that a lot of my symptoms were actually undiagnosed ADHD, I only really knew it as the 'rowdy little boy' disorder), you can take a peak at this adult ADHD screening questionnaire: The Jasper Goldberg
Obviously, no one here can do any official diagnosing, so if anything from the above does resonate, it'd be worth a trip to the doc to see what next steps might be!
As @Snowie mentioned, fidget toys and the like have been an absolute game changer for me as well - I have soooo many, for all kinds of situations. Some that are quiet and subtle (for meetings and stuff) and some that are all about the texture, some that are just satisfying to click/tap/etc., they really help. The kid's section in Kmart actually seems pretty well stocked with fidget/sensory toys too, at least my local one is. Frequent stretching breaks and regular exercise also really help.
Let us know how you go with the kinetic sand! I quite like it myself, but it's a bit messy so I never ended up buying some... maybe I will tho hehe. Playdough is also really fun! It can be kinda nice to get a little silly, let our inner child come out to play along the way too 😊💜