Why does it matter how you grip a golf club? Can it really affect your performance whether you interlock or overlap? Yup. A golfers grip is one of the most important factors in their ability.
How would you grip a baseball bat? How would you grip an ax? How would you grip a hockey stick, a pen, a spatula? There is a correct way to grip everything, because all these tools are used for different activities and have different purposes that require different motions.
Would you grip a pen with the same pressure you would an ax? Nope, that's why grip pressure is so important and differs greatly based on what you are gripping.
There are two main ways to grip a golf club: interlock and overlap. Some of the greatest players ever interlock, and some overlap. You just need to try both if you're a beginner. Everyone is different, some people like interlock, some like overlap. It is all feel.
But please remember that grip pressure is key, it is easy to forget this. On a scale of one to ten, your grip pressure should be about a 5 on full swings. Anything short of a full swing it should be even lighter, like 3 or 4. While putting you want your grip pressure to be as light as it possibly can be. Here is a link on how to grip a golf club that we think you will find helpful.