For Vinyl digitizing you need:
A good turn table. Phono Cinch works on lower voltages than tape deck or others, you need a preamplifier for connecting to a sound card or a professional sound card with preamplifier.
You can get turntable decks as USB device, but the quality is questionable.
WAV is fine and can be player with window player. FLAC is a lossless codec saving about half the file size, again Windows Media Player can play that nowadays with FLAC codec. In the age of MP3 you may also convert your WAV files to MP3 or other compressed formats for easier transfer to player devices, but as with CDs you may keep the original recording in CD quality (44k samples, 16 bit) or even higher. Depends on your sound card capabilities.
You better can avoid a ground feedback loop resulting in noise. This can easily happen as you connect computer and hifi, which each have their own ground. You may get some impedance filter at a hifi shop of your trust.
Bye, Olaf.