Layout is not centered and is off to the left

Hi, I have just activated the DW Timeline theme on my wp site and the layout is not centered and it’s off to the left? The image at the very top is centered and all the text is as well, but then when it gets down to my posts, the main line that the posts branch off of is over to the left side of the page as are the posts attached to it. The contents of the posts are also smaller a bit smaller than the live demo/preview? How can I fix these issues?
Thanks! Ally