@DrewTaft
Hi, Drew.
When Homing is enabled and the machine is turned on Grbl goes into the Alarm state which shows up as the Alarm state in UGS because the software has no idea where the hardware is positioned. You have to Home the machine($H) to clear the Alarm. Once Homing is accomplished then the software is synchronized with the hardware and knows where Machine 0,0,0 is.
You can check this thread for more information. It is one of many threads on this topic on this forum.
Breaking homing switches - slamming the spindle to a rail? No need to