How long can we expect until the beta invitations? Super exited 
remember that you can’t download code with a usb cable from the computer directly to the cortex on linux, use the programming hardware to go from the computer to joystick and then to the cortex (either with vexnet or a direct USB connection). then you can just run make upload from the terminal, if that doesn’t work try running make upload as root, if running it as root works then it’s a permissions issue and you probably just need to add your non-root user to a specific group that has access to the device representing the programming hardware in /dev (for me ttyACM0 on any linux system I’ve used on my laptop).