Need help aligning content

I am trying to get my website homepage as close as possible to the attached image website layout. I do not know how to align the content like the attached image. Some of my images and content are shifted to one side or another and does not fit neatly in the content area. On the attached image, there is a green block that stretches along the top area and behind the sidebar, and more of the striped background is visible on the bottom part of the page.

I don’t know if the sidebar can be shifted far left like the attached image. Any tips to get this fixed are greatly appreciated!