My car is having trouble starting up the starter is making fkat buzzing sound any ideas?

Sounds like a slipping pinion gear. Remove starter solenoid assembly and put on the kitchen table, old newspapers for protection are optional. The pinion gear is the one on the end of the starter motor shaft that is driven forward to engage with e toothed edge of the flywheel. It should free wheel in one direction and lock solid when reversed. The locking clutch mechanism its what supplies the motor's rotation to the flywheel to crank the engine over. If the pinion gear clutch is slipping the motor makes a whizzing sound as the shaft spins within it. You can buy a new pinion gear cheaply. Whilst the motor is out buy a refurbishment kit ($10) for the solenoid consisting of contact striker plates and plunger . This preventative measure will avoid any hassle in this department for many years.