If you only ever learn one scale, then it has to be the major ... then E, G and finally the next C note. Going up and down through the notes gives you: C E G C G E C. Repeat the pattern with D, F, A ...

So, a C major chord uses C, E and G notes. Play through the scale, then, to work out the notes of the chord ... No surprises there - the guitar has six strings, after all. As long as you play a ...