Where/how to start?

You do not want to do anything by Bluetooth. You want to use Qobuz service only. While you can rip your CDs to files and store them on a streamer, or network attached storage, or USB drive… this is all old tech.

You want a streamer… like an Aurender N10 (of Bluesound for a budget solution). If your router is not nearby… then just buy a cheap wall wart WiFi extender (~$59) at Best Buy or Amazon. And plug the streamer into this. That is it. You need not worry about files, storage, ripping files, or any of that stuff. PM me if you want to talk about more specifics. Or show phontos of your equipment and setup in your profile and we can be more specific.

Why not buy a subscription to Tidal and stream lossless through your Oppo?  You already have everything you need to get started except the Tidal subscription. Then as you get the urge you can upgrade the streamer, DAC, etc. til your heart's content :-}

The standard "starter" answer is get a Bluesound Node and Tidal Subscription $~600). I prefer Qobuz but note sure if Node supports that. Node got all you need to come out of the gate for your first experience. Just run RCA into one of your Pre or use one of the Optical in on the Oppo, DAC proly better in that unit than the Node. Stream with that while you acclimate to the digital landscape. 

Got wired ethernet at your 2 channel set up or Wifi?

I agree , get a Node .   Its great for the money.  If you have a large CD collection maybe look at the Bluesound Vault 2i and you can easily archive all of your CDs.  Put a CD in and it rips it to an internal HD.   I love mine, it and the Node can be controlled from your phone. PC , Tablet.   Easy to use .   

You definitely want to ditch the Bluetooth and use a service like Qobuz.   

Thanks.

It appears that Bluesound Node (N130?) + Tidal subscription using OPPO’s DAC is one of the best (simplest and cheapest) options. Once I get used to the streaming music, I’ll think about upgrading to a more high end streamer.

[edit] I came across Cambridge Audio CXN V2. Would it be better in sound than Bluesound Node? Having a display feature seems to be very convenient.

My Ethernet router is far away from my components. Then, I can use a wall wart WiFi extender?