I had the similar Edge 305, they have 'bread crumb' mapping, a dotted line to follow if you've uploaded a track. They don't do real time tracking but they record your track for upload to a home computer.
No and No.
A Garmin Edge 205, even though it was a top bit of kit for it's time is now pretty much obsolete. Now replaced by the Garmin Edge 200.
It doesn't have maps rather then you follow a pre-loaded 'breadcrumb' trail ie a black line. It will beep at you if you turn off course (the line)
I can't remember which Garmin's have real time tracking but check out DC Rainmaker's blog as he reviews in great detail all the Garmin GPS units.