Hitting the ball with the bottom of the club face can result from several different swing faults
Get your hands on the club properly and learn the correct grip pressure by sliding two tees between your thumb and forefingers and hitting balls without dropping the tees
A great visual drill to fix an outside in swing path is to place a string on the ground to represent the target line and place a head cover just outside of the line, this will visually help you keep the club inside on the downswing so that you do not hit the head cover