My friend agreed to a date!! What now?

Don't push it. Never do. If you did everything right and asked her out right. And she/you know its a "date" and not a "hang out". This would be your first date. DON'T MESS UP by coming ON TOO STRONG. If she likes what she sees in you on the first date, chances are there will be a second date probably within the same week. So let the dating process continue, then when the time comes (like after 2+ dates at least, or 3) then you can probably or most likely be "official bf/gf".