If you plan to use a raspberry pi, I do recommend using webcontrol over ground control to overcome compatibility issues with the kivy module ground control uses. I would even use it on a windows pc/linux over ground control, but I am a bit biased.
As for first steps, once you get webcontrol fired up, check out the help section and let me know if it doesn’t get you where you need to be but I will give you an extra tip. After you do the Quick Configure, upgrade the controller’s firmware by going to Actions->Upgrade Holey Firmware. I will be updating the documentation to indicate that.
If you want to see webcontrol’s help documentation, its all online at:
https://madgrizzle.github.io/WebControl/
This documentation is embedded into webcontrol and you can reach it via Help->Offline Help… just note its only up to date with what’s online as of the date the software release was created.
To reach webcontrol, assuming its running on the RPI (or other computer), you just need to browse to the RPI’s ip address at port 5000… (i.e., http://xxx.xxx.xxx.xxx:5000).