Fill in the gap in this digital chain

I am new to digital music and I need help understanding what options I have.

Let’s say you have a Denafrips Terminator DAC hooked to your preamp.
What are my options of getting music to the DAC?
I know I can hook my MacBook into the DAC and control it from my phone, but
I want a more permanent option. I’m looking to use high quality streams only, no purchases.
I like the look and function of the Roon software as well, seems to add a nice tangible touch to the digital world.
What do I need to fill this gap? How will this effect the sound signal if at all?

Thanks