Another chord you come across every day, the E major chord is fairly straightforward to play. Make sure your first finger (holding down the first fret on the third string) is properly curled or the open second string won't ring properly. Strum all six strings. There are situations when it makes sense to reverse your second and third fingers when playing the E major chord.
Unlike many string instruments which use a bow to create a sound, guitars are played by plucking or strumming the strings on the instrument, which vibrate to create a sound. Chords are played when the guitarist holds their fingers down on more than one individual string to change its length, which in turn changes the frequency of the vibration created - in other words, it creates a different note. Performers often use guitar tabs, rather than sheet music, when learning music: this acts as a kind of 'map' to teach guitarists where to put their fingers on the strings.