Width change for new page

Hi, I have a separate page on my site that’s content separate from my main page. I am trying to insert an iframe on that page but it clashes with my sidebar. I want to change the content width on this page only and not have it affect any other page on my site. Is this possible at all? I am not very good at editing wordpress files so if I could do this via html or a setting change in the dashboard it’d be able to do it myself. Thanks in advance.