Reaper DAW I/O

Can anybody help me into and out of Reaper DAW?

I just had a Windows upgrade that shredded my previous sound I/O settings. If I do anything in Reaper I have to shut it down to get audio off my browser. Even worse was if I watched a YouTube tutorial about Reaper I had to shut down Chrome to open Reaper. Considering that I like to switch back and forth to apply what I'm seeking to learn, this was unacceptable.

So I downloaded Voice Meeter Potato and the first virtual cable. I use a Behringer Xenyx mixer as my USB sound device. It works both as a USB input and output but at this time I'm primarily interested in getting from the mixer into Reaper and from Reaper into my computer speakers. My computer is a Gamers Republic PC and has plenty of speed.

I got my mixer/mic into Potato as well as my browser and I got both of them into OBS but Reaper is confusing me. Help ! ! ! I plan on using Reaper and OBS for music-making collaboration but can't get anything into or out of Reaper.