Servos are usually controlled using the Servo library. It does not need to use the PWM pins.
If your drive motors are DC motors then you will need an H-bridge motor driver for them if you want to be able to go both forward and backward. Forward only would just need a couple of MOSFETs.
That sounds like an ambitious project for someone with no experience but most of it will have been done before so Google will have plenty of useful information. Good luck.
Steve