Help

I am really struggling with this nav unit. I pulled the radio out and I believe the red arrow is pointing at the gps antenna that is plugged into the back of the radio. But also on the nav screen it is showing the gps with a red line through it. I kinda got the nav to work somewhat. It will recognize addresses and routes to get there but no matter how much I try to calibrate where I am with the little triangle it never stays on the roads. It will be close at first but the farther you drive the farther away it gets. Does it not automatically sync where you are to the map?