I have tried every way (I think), but I can't find a way to retrieve Lat and Long after I save it. For instance, once I have a location, and want to give it to a friend, I can't get it. What am I missing?

I don't know if it is the only way to get coordinates of stored waypoints, but one possibility is to set the device to GPS simulation mode, then select the waypoint and "Set Location". Then you can see the coordinates e.g. in satellite almanac or "Where Am I" function.

You can also look on PC in current.gpx file (e.g. by using MapSource or BaseCamp).