M.G.
 
My plans for this weekend was to get a functional understanding of X3 (where I could at least lay down some tracks).  First major issue: I recently upgraded my computer... OS, CPU, graphics card.  I'm now running Win 10 64-bit, Ryzen 5 1500X, GeForce GTX 1050, ASRock X370 Killer SLI/ac motherboard, 8 GB RAM, etc. 

Your ASRock X370 has onboard audio 7.1 CH HD Audio (Realtek ALC892 Audio Codec).
 
Enable this in the BIOS and plug some conventional amplified speakers or headphones into the 1/8" audio out from your motherboard (the green jack on the rear i/o panel).
 
Then try the WASAPI or MME driver modes with this audio output.
 
If you don't like the audio latency with these options, you can always try ASIO4ALL until you get an interface.  Be sure to uninstall ASIO4ALL before attempting to install an audio interface and the supplied real ASIO drivers!!!
 
[Edit: I think you can bypass the USB hookup, and using the DAC in your motherboard's Realtek audio codec, just connect to the 1/8" aux-in connector on your powered speakers].