AS a music producer you can never have enough free sounds! In the beginning you have to build a palette, try out which sounds suit your style of production, etc. Later in your career, you will have a set of signature sounds, but you need to find inspiration and move forward, otherwise people will copy your predictable production recipe.
The sounds are usually supplied in WAV or AIFF format ready to use in 99% of software and hardware. They come in a ZIP file, which you can open in Windows, Mac or Linux with no rpoblems. Sometimes it’s best to have a special ZIP software like WinRAR or Keka, because they especially handle large Sound Pack Libraries better.