The front end of your car will have "Zerk" or "Grease Fittings", that allow you to apply grease via a grease gun into the high wear points on the golf cart. For example, Club car will have 5 fittings, all of which need to be greased at least once a season.
You do this by attaching the grease gun nozzle over the fitting and pushing until it clicks in place. This will allow you to pump grease through the fitting into the metal on metal wear point. If the gun does not seat fully on the fitting then the grease will not penetrate the fitting and grease will be pushed out around the nozzle, making a mess all over your gun and the golf car. Once it is seated properly, pump the handle on the gun until grease comes out of anywhere else but the tip of your gun. Repeat this process for all grease fittings on the golf cart.