So I'm trying to connect my USB network adapter to Linux so I can scan for networks in my virtual machine. I do not want a bridged connection, I've had no luck so far looking for options which allows me to do this.
"USB network adapter" is a generic term, there are many types in that device category! What type of USB network adapter are you referring to and if it's one like a USB Wi-Fi Network Adapter has the drive/software for it been install in the Guest OS and is it connected?
I have a friend that is very happy with his usb-ethernet dongle. He runs opensuse. It should work very well for you.
JUE130 USB 3.0 Gigabit Ethernet Adapter
Is that what you wanted?
I think your requirement is that the virtual machine can detect the USB network adapter and config the USB network adapter to NAT or Host-only as the virtual network adapter, right? If so , i think Workstation indeed have no such option to do that. If you just want to change the USB network adapter's ip address in the virtual machine, i think you can change the ip address in the VM system.