If you are just starting out, you could look at setting the PC up for a multi-boot option, one for movies, another for your music and finally the remaining part for archiving your CD's and movies. (you will need Window's 10 Pro for this as you can install the same copy of Windows on each boot without any extra cost.
Also look at a couple of programs - AudiophileOptimizer and Fiderlizer (opt for the paid version as it supports the developer

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With HDD, look at quiet ones, Western Digital 5400rpm's seem to be one of the quietest ones on the market.
For archiving your music, dBpoweramp is a good place to start. It's simple to use. Try a few formats to see which one best suits your system and your ear. They're not supposed to sound any different, yet people can hear the differences between musical formats.
WAV is an original uncompressed format. ALAC is Macintosh's and FLAC seems to be very universal with the ability to tag information unlike WAV If you opt for WAV, then dBpoweramp will tag most of the information for you, If not, you can ask it to search the disc and it will add that info.
For playing, use a program similar to jRiver as it understands the tag options for WAV files (if you choose that option) and if it cannot find the cover, you can simply add it in that program and it will then copy it to each of that albums tracks.
You can also look at the AudiophileOptimizer user manual PDF as it has some further information on how to set up your PC for musical playback
For Movies, I use PowerDVD 18. I did try Kodi for a time and just didn't get on with it. Both PowerDVD and jRiver have remote control options via compatible smart phone/tablet devices too.
I shall let others explain how to archive movies as they may know better than me as I do not play anything other than HD movies and have not moved over to 4K even though I have a 4K TV
If you do select to create a multi boot PC, then just install the bare-bones regarding software as the lest amount of programs on it means the least amount of background threads and processors running which all help musical playback. I've been doing it for many years (since USB DAC's became good) now and would never look back at a conventional CD player unless something very special came along
