Controlling arduino MEGA with an iPad and read Bus CAN informations


I'm new with Arduino and want to learn a lot about it!

So here is my project:
I want to mount an iPad as a dash in a car and it would replace the head unit and the ac controls.
And if possible, i also bought a shield bus CAN module and want to show the basic infos (RPM, coolant temperature...) on the iPad or if not possible on an Arduino LCD screen.

Does anyone have ideas on how to connect an iPad and command digital outputs of my Arduino mega because i bought an HC-05 but it is not compatible with IOS... so is there another way?

And my second questions is where can i find infos on programming a can BUS shield so i can read the infos on iPad or on a LCD?

Thank you