1) Windows Sandbox: I tried to enable it, but the setting just isn't there - at all. After some googling, I discovered that if a system doesn't have it as an option, apparently it just won't show up. Well damn. It does, however, list "Virtual Machine Platform". Might that work? Even though by default its already enabled.
(UPDATE: I'm going to try to install Windows 11 on VMWare. Surely that will work. I'll let you know the results.)
2) As for my antivirus, since its a new computer, I'm just using the Windows Security stuff. So basically, just what Windows has built in.