I haven't found a way to plot my own position on the radar screen.
The previous post will tell you how to make a dot at your home location. You can then use the right click menus to measure the distance of something from the dot. GRLevel3 also has provisions for hooking up a GPS receiver so you can plot your position while mobile.
There's not a lot of documentation for the program. You kinda have to poke around on the menus and see what happens. Also, check the forums on the GRLevelX web site. Once you register, you can get access to the registered users only forums. I learned a lot about the program from reading the forums. Somewhere in the forums, I found out how to import Tiger map data so I can get street-level maps under my radar images.
A couple of neat features. In the Warnings window, double click on a warning and the program will jump to the radar site nearest the warning. And, if I remember correctly, hover over a warning in the Warnings window and a pop-up will appear with the text of the warning.
I run GRLevelX in four-panel mode on a wide-screen monitor so I can see Base Reflectivity, Storm Radial Velocity, Tops, and VIL all on the screen at once.
One thing to keep in mind about these programs...There is always a lag between what you see in the radar image and what's happening in real life. You have to learn to anticipate what the next volume scan is going to show you.