Can't get rid of this box in the header

Hello,

I can't remove this box to the top right of my website in the header that says 'get started'. This page was a pre-formatted page that I was able to edit. There is no option when editing header to do anything to this box it doens't even come up. I've deleted the page but the pesky box is still there. Any tips/help would be greatly apprecaited!

This button is set in the header settings, this support article should help:

https://support.squarespace.com/hc/en-us/articles/360000667707-Building-a-site-header?platform=v6&websiteId=6381f1ab7fa4241832915ff3#toc-add-a-button-to-a-header

THIS is so helpful. thank you!! I'm such a newbie when it comes to designing websites so thank you 🙂

Can I ask a seperate question here: I am struggling to embed a youtube video into my website. I have used the link from youtube into a video box but it does't upload it. and it's only 16 mins. It says . Any ideas? 

• Unable to retrieve video. Replace link or try again.

Are you trying to add the video as a link?

https://support.squarespace.com/hc/en-us/articles/206542397-Adding-videos-to-your-site#toc-option-1---embed-videos