I’m going to pretend you’re asking in good faith and would genuinely like to learn.
“Stimming” is “sensory stimulation,” or self-regulating behavior. When used in this context it’s not sexual. It helps (typically neurodivergent, but I’d argue most) people better process the environment around them by having a sensory input they can focus on.
Examples of stimming are hand-flapping (waving one’s hands around), clicking a pen, listening to music, tapping one’s toes, chewing gum, just to name a few. I’m willing to bet you have stims that you may not even realize, and that’s perfectly okay.
TL;DR: Stimming = fidgeting that helps you focus/calm down, it’s not perverted.
Buying anything from California will also teach you this.
(They put cancer warning stickers on everything, for anyone not familiar)