Hi,
One thing you should know is that there is nothing like a CAN peripheral inside a microcontroller which you have to write a code for.
All you have to do is to use the basic peripherals of a microcontroller, use the basic codes, modify them slightly and implement your CAN network.
Suggest you to start with basic coding of 8051, this link will help you to speed up the process
http://www.engineersgarage.com/microcontroller/8051projects/list