Removed right-side menus – need help adjusting the width of the txt

I am working on a site for a good friend of mine. the address is riverbottomretrievers.net. I removed the menus that were on the right side but now have a blank space and want to expand the area for the txt so it fills the whole screen.

Also – where it currently says River Bottom Retrievers in txt at the top – I want to change that to his logo – is it possible there? Thanks in advance.