I have not looked through the XNC manual for many years but most of the Biesse controllers that I have used are more similar to each other than different. I assume the tech did a full install on the machine leveling, calibrating origins that sort of thing, run test programs?
If you have had the machine booted up there should be an editor window to start writing programs. you need to name program and start by filling in the blanks on conversational windows starting with X,Y,Z part size this should all be outlined in manuals though you should really go through that first at least the writing programs and tooling machine + run environment.
Seams the XNC owners manual was adamant about shutting down the XNC before turning off power so keep that in mind.
I would need to look at the manual myself to make recommendations. You probably do not want to try to run any programs before making sure tooling is correct and of course you will need to home the machine before running. These are real basic things the tech should have shown you in just a few minutes.
After booting the running screen should have a global homing button. I know my NC1000 takes quite a while to fully boot and show ready to run or home.
Like I said though I will need to look at that manual to see what screen should look like.
Paul R