Chords are built on scales, using the 1st. 3rd, and 5th degrees (that is for the basic triads). So, if you are using a Major Scale in the key of C; you have the fallowing notes: C D E F G A B C

Take the root (C) and build a triad. now you have a C Major chord made out of the C E G notes.

Now take the second degree of the scale (D) and build a triad, the result is a D minor chord, made out of the D F A notes.

The third degree of the scale (E) gives you an E minor chord made out of
(E G B)

The fourth degree gives you a F major
The fifth degree gives you a G Major
The sixth an A minor
The seventh a B minor chord

You can play those chords in any order and use your C major Scale or the relative minor wich is the A minor scale, and you will sound great.

I sugest that you use the Circle of Fifths to constuct your chord progression. Have Fun