Brand New MacBook Pro almost full with "System Data"

My MacBook Pro has been out of the box for only about 4 hours, and my 1TB SSD is almost full. I checked "About this Mac" and in the Storage tab it shows 910 GB of "System Data." By comparison, the second-biggest chunk is Apps which is taking up 46 GB. I've read through these forums and other posts and tried CleanMyMacX which deleted some stuff but really didn't even touch the "System Data." From this forum, I ran the suggested EtreCheck Pro and as far as I can tell it tells me only what I already know -- my SSD is almost full and it's lagging my machine. I downloaded/installed Microsoft 365 and some of the Adobe Creative Cloud apps (not all). My iMac desktop also has a 1TB HDD and I'm nowhere near filling it. How can I remove the "System Data"? It's almost the entire drive.