Piano Black theme. PLEASE help with sidebar issue

I am build a site for an employer who loves the Piano Black theme. On the home page, he wants two large videos, then a slideshow. I enter the video size we want but it covers and overlaps the info in my sidebar. Is there any way of pushing the side bar down under the media I add? I tried moving sidebar stuff in the “down” area in widgets. But it didn’t see to work. Please help!!!!!!