Heyo friend! If you want to download some vst there's a good website called rutracker, where you can download them via Torrent links. It's a russian site but you can translate it automatically. I got mostly all of my VST there.
For creating them, well you can "modify" via oscillators and waves like Vital or Spectrasonics, but those are VST you have to download too.
If you want to contact me concerning the type of libraries and vst you want, don't hesitate!