Initial Setup Failure with PixFalcon and QGC

Hi, first time posting and just wanted to say thanks for having a support community like this!

I am trying to setup my new quad that has a PixFalcon running with an Odroid XU4. When I try to setup the PixFalcon on its own (nothing connect except for USB going to my laptop running Ubuntu 18.04 LTS), I get the following situation:

All QGroundControl connections to vehicles must be disconnected prior to firmware upgrade.
Please unplug your Pixhawk and/or Radio from USB.
Plug in your device via USB to start firmware upgrade.
Found device: PX4 FMU V2
Error: Open failed on port /dev/ttyACM0: Permission denied
Upgrade cancelled```

Just to reiterate, just trying to do initial setup (my goal is to get it flying RC soon). Any help would be appreciated!

Did you remove the modemmanager and do the dialout group setup?