To deliver the club correctly on the downswing you must first learn the three arcs of the backswing so that you get your club in the correct position at the top
Making a proper putting stroke is the easiest part of putting, using the Putting Arc will teach you how to groove your stoke so that it is perfect every time
Slicing is caused by an open clubface, fix this by turning your top hand clockwise and practice swinging with a closed clubface