(Actually, only one.)
The grip is the first fundamental of golf. Get a good grip and building a good swing is much easier.
A vital grip fundamental that you never hear about is to hold the club at its balance point.
If you put your hands on the club about an inch from the top of the handle, you will find a place where the clubhead feels like it is an extension of your right hand.
Above this point the hole club feels whippy. Below this point, the club feels stiff and unresponsive. In neither case do you feel connected to the clubhead.
Be sensitive in finding this balance point. Sometimes moving your hands just a quarter of an inch up or down the shaft makes the difference. By holding the club at its balance point, it will feel like a tool in your hands ready to do your bidding.