How to move 5 dots (that appear one after another) on a path and then disappear the same way at end?

Start by setting up your dashes and gaps to get a dotted line. Then, set a Dashes/Offset keyframe at zero and another a few frames later, moving the dots to exactly five spaces. Then add trim paths, set the first Trim Paths/End keyframe at zero,  then move down the timeline, and set a second keyframe for the end to a value that reveals the five dots you want to move and the Trim Paths/Offset keyframe to zero. Move down the timeline to where you want the first dot to reach the end of the line and just the Trim Paths/Offset value to move the first dot to just before the end of the line. 

The last steps are to duplicate the Trim Paths/End keyframe, move down the timeline the same amount of time between the first two keyframes, and set the Trim Paths/Offset to 360º and the Trim Paths/End value to zero.

That should give you something like this:

It's a slightly more convoluted solution than Mylenium's text on a path solution, but it will give you the option to make the dashed like look any way you want it to look.