How much two by fours what I need if I have a shed that is 15 feet wide and 45 feet wide long?

Hire a carpenter. He will know everything you need, such as how much wood, where to put braces, and how to comply with the building code. He will charge you, but it's cheaper than a building that falls down or catches fire and is destroyed before you can make a phone call. My neighbor built a shed in the back yard and the first wind we had lifted it over the house and into the street.