When you click "Create Private Match" we'll spin up an private server, to join you'll need the lobby ID.
You'll need to note/type/copy your private lobby ID from the "Ready Up" screen and give it to your friends/scrimmage opponents.
A fully featured and easier to use system is coming soon, but you die hard try hard proto pros have been asking for this and you deserve it. The next tournament (Mid November) is going to have some serious prizes!
Also we know private is misspelled in this update, you try spelling at 3am with no coffee! ;) We'll get our English together soonTM...