I recently set up a NAS—network associated server-and am currently burning CDs to it. I added dbpoweramp to burn the CDs. I compared one CD that I had ripped in iTunes to the same ripped with dbpoweramp and it wasn’t a subtle difference. The dbpoweramp rip was so much more alive with presence and impact.
It was like everything else in Audio—the iTunes sounded fine until you discover what you are missing. Dbpoweramp is also better at finding metadata.
I use Audirvana Plus for playback. The 2 programs together cost about $150 and IMO justify the expense, but you sound as though the budget might be tight, and you would definitely need a new computer. You may just want to stick with iTunes and get an accessory hard drive for now, and if you can, save the CDs and re rip them later when you can afford to upgrade, or after spending some time investigating what works for you.
Alternatives to consider are streaming services, such as Tidal, or dispensing with the Computer and dealing with an audio component customized for digital playback and/or ripping