In Blender 3.1. geonodes you can convert mesh to curve, then resample curve and put "Circles" along it with "Instances On Points" node.
If you want to make "Circles" appear one by one along curve, you should play with "Endpoit Selection" node.
But the most practical way to get the same effect is to use array modifier instead of geonodes. This way works in all versions of blender. And you need not to use single edge to do that.
So you should use array if you have just one single edge going along x axis. But your question became more reasonable for me if you have some geometry object with intresting shape and if you need to place your "Circles" along detached edges of this object.
In this case you will need a bit more complex node setup. In the example below i use "Curve To Points" node to rotate instances along edges. And i use "Not" boolean math node to invert selection, for remooving "Circles" near ends of the edges. And i have to use "Capture Atribute" node, because "Curve To Points" node prevent me to apply "Endpoit Selection" node directly to the "Instances On Points" node, because instances in this case are placed on the points but not on the curve.