Try to keep the first finger of the left hand straight and parallel to the frets. It is important to keep the other fingers arched and use the tips of the fingers only.
The left hand thumb must be kept behind the neck in line with the first finger so that it can apply enough pressure to hold all six strings without "buzzing" or "dead" sounding notes. Bar chords are difficult to play at first but with practice you will find that many bar chords are easier than some open chords to play. Bar chords are easier to play on an electric guitar and the higher frets.