And another question about visual basic 2010?

So, I am nearly finished with my project now but I still have two problems. My first problem is that I can't find out how to make my combobox show a default item when the form starts. I typed in the collection of items, but it doesn't show the first item on startup.

My second problem is that I can't find out how I can make a result that i got in the first window transfer to the second window (I am making an app with two windows, in one it calculates the price of one pizza and in the second it is supposed to calculate a price if the user wants to buy more than one pizza. I know, I could have done both in one window but it is a school project and I must have two windows, excluding possible messageboxes.)

Any help will be greatly appreciated.