When you say “i made my first track” what does that mean? Where did you make the track? Im assuming you created a GPX file somewhere and loaded it to DMD2 app correct?
If that is so, there is nothing to “start” it, you just go to wherever is the track or route start and then follow it.
If the track start is too far away you can start a navigation to the beginning of it: Tap GPX > Select the file you loaded > Tap “Tracks” or “Routes” (depending on the file content) and then select “Navigate to” to start navigation to the start… or simply press and hold on the map wherever is the start and a dialog shows where you can select “Navigate”.