music server questions.

Hello. I'm considering some type of music server device. I have no experience with such things, and searching so far has not brought me much understanding. I want to use it into an RME ADI-2 DAC via usb.
Here is what I want:

A good amount of local storage for wave files. 
Ability to play files from a memory stick. 
Ability to play audio from the internet, Youtube etc.
Remote control from Android phone and tablet.

Here is what I don't want:

Onboard dac
hires streaming or any subscription plans.
apple products.

What should I be considering? Any advice appreciated.
My setup meets your requirements. As a server, I use a QNAP NAS, which comes with apps for a one-click install of several music/media server packages. I run Minimserver for home and Plex server for remote access.  In general, this is a much lighter install than Roon, and involves no Apple products.  QNAP has its own media server, which I've never tried.  You could also try Bubble UPnp Server, which should work well with the control point I'm recommending. I've never tried that either.

From an Android Tablet you can run Bubble UPnP as your control point, it will see Minimserver and Plex, and it will broadcast to all DLNA renderers and Chromecast (perhaps more, I'm not sure).

If you have WAV files, you may need to also enable Minimstreamer for format conversion to certain renderers/endpoints- I'm not sure whether all your renderers will accept them.  My library is about 1100 FLAC albums and 100 or so DSD (.dsf), so only the latter ever require transcoding.  Plex, I believe, will also let you set some transcoding options.

If your collection is well tagged, and/or contains classical music, Minimserver is an excellent product. If it isn't, Plex, like Roon, will supply a lot of the metadata on its own.  And if you have video, or require remote access, Plex is far superior.  Any of these servers should show up in proprietary player apps (like Cambridge Audio, Muzo, Krell, etc.)
Thank you for the detailed response. I have a lot of reading to do.
Also, I don’t have a collection of wav files at this point. It’s something I intend to do once I have the server in place.