Helps with Website

As I have been working on my website I have found that a lot of the things are a lot easier than I was anticipating. However, I am stuck on a few things. I don't know how to put in a calendar, I know you go to insert and click calendars but do you have to make it before? And if so how do you do that? Also I need to move a page that I have already created, I have it as it's own page on the sidebar but I want to move it to a subpage under the homepage and cannot figure out how.