You are right. Draw or create the shape. You can do it with a mask and apply the stroke effect if you want but it's probably easier to
just make the shape with the default stroke on it then use the Trim Paths effect to have the stroke draw on.
Next creat the circle and, select the stroke path in the layer controls & CTRL-Copy then CTRL-Vpaste onto the position attribute
of the circle. This will paste the keyframe info of the stroke onto the position of the circle. Finally select all those keyframes & Alt-Drag
them out to match the timespan of trim path key fames.
Let me know if you have any questions. I made a video but accidently rendered it at half resolution and don't have time at the moment to re-render it.
Screw it: Here's the video even though the resolution is crud
Thank you for the detailed video!
I think I get what you are going with, I'll have to try it out myself, but I think that answers my question
The part where I creat the trim path is confusing because the "fill" is turned on and the stroke is black against a black background.
Where the video skips all I did was turn off the fill and then change the stroke color.
The reason the video cuts is because it took me about 30 seconds to figure out why I couldn't see the stroke. LOL