OpenCart change

I want to do something when you give the customer click on add to cart, I want them displayed on Checkout page, the product in my cart goes up and then I have to click on the cart to take him there to order .




I would like to know how to minimize steps order, to be a maximum of two steps for placing comenii to unregistered users such.
I want to know how to remove or zip code automatically without having to fill customer.

Thank you!