OpenCV Detecting points along curved lines

I am new to openCV programming and I would like to do something which seems fairly simple in my mind but I haven't found any useful solutions.

I am building a robot that needs to follow lines on an image drawn by a user. Let's use as a reference.

Obviously, the line will need to be converted into points in order to navigate to. I have attempted using Houghlines but that seems to only work for straight lines. Using contours seems promising to me but the result I get from findContours is a set of points on either side of the line such as: I am not surprised as this is the definition of a contour.

My question is, is there a way to detect points along the line and not on either side of it?

Thanks!