How to embed Vimeo hubnut into wordpress?

So i was provided with html code of vimeo hubnut widget and it says I need to embed it into my html code. The problem is I don’t know which file exactly i need to edit. Any suggestions? Oh, I’m new here to clarify, so go easy on me, I have a lot to learn about setting my web right :)I’m hosting on bluehost.com, if it is of any importance in this matter.