Hi @Blendash ,
Maybe you should (re-)take the Animation Bootcamp: https://cgcookie.com/courses/animation-bootcamp
Those rolling circles inside a larger circle, is what a Spirograph does. Erindale covers the underlying math in some GN tutorials…this one, I think:
https://www.youtube.com/watch?v=caJEXmreLnM
or maybe the older one:
https://www.youtube.com/watch?v=JdkH9EkhEwQ&list=PLVm7O9OzjT6EIDtFGC67QxGsHkz3_RbIw&index=51