1) When you installed the uSD card, it should have asked if you wanted to format it for maps or routes. I assume you told it 'routes'.
2) Go to the main menu and slide right a bit, do you see a button called "Start Recording"? If so, press that and start moving.
3) A solid (NOT blinking) red dot should in the upper right corner of the map or menu screen. A blinking dot indicates inability to record a route, possibly due to lack of a GPS fix.
4) When you are done with whatever travel has created your route, go back to that same button which should now have changed to a square and should say "Stop Recording". Press that.
5) You can now give your route a name or leave it with the date/time name automatically supplied.
6) Finally, hit "Add" in the lower right corner of the screen.
7) Now, from the menu, select the "My Routes" button. You should see an entry with whatever name you supplied, above.
Now .. at which step is the process failing for you?