Questions on using VO on mac book air
Applevis has great resources on getting started with the Mac. In fact, there's a page dedicated to new Mac users you should look at.
As to typing, I'm not sure what you mean. The typing mode on iOS is the difference between touching the character you want and lifting your finger, and double tapping to enter the character. The Macbook Air has a physical keyboard and so has only one way to be typed on, namely, pressing the keys. Sorry if I'm misunderstanding you here. If I am, can you please explain further?