Playing Cs maj chord on guitar is easy. Just place your fingers on the strings like in the image below. Scroll down for a video guide and detailed explanations.
Your index finger is your first finger, middle finger is your second finger, ring finger is your third finger, and your pinky is your fourth finger.
The name of the thickest string, the sixth string, is E. Moving on, the fifth string is A, fourth is D, third is G, second is B, and the first string is E.
The frets on the guitar are the metal strips placed along the fretboard. The first fret is the metal strip closest to the headstock of the guitar, and then it counts up from there.
Crosses indicate strings which are not to be played. Number left of the diagram shows the starting fret. Dots and numbers below show the position of fingers.
Video Guide Explaining Guitar