Whilst leaning all the scales will be of great help in your playing, and probably understanding, the main one for this purpose is the major scale. Chords basically are made up of 1-3-5 of a scale. These are triads- 3 notes. Using the major scale, these will be major chords. To get minors, you could just make the maj. 3rd into a min. 3rd, rather than use the minor scale - the end product is the same.
Chords with numbers - C7, C9 etc. will use the extra number note of that scale as well, although various rules need to be brought into play as well.Slash chords will be the basic chord from the first letter name, with the second letter name as the lowest note played, sometimes as an extra note to the chord.
There have been numerous questions pertaining to this and related questions on this site, so not going into more depth right now.