I am having some issues adding the HubSpot tracking code to the website, it keeps breaking the theme. 

https://knowledge.hubspot.com/articles/kcs_article/reports/install-the-hubspot-tracking-code

This links shows you what I need to do.

When I edit the page with Wordpress and add the code it wont show, if I add it a few lines in it break the theme. Any suggestions on this?

Hi,

The problem is that you need to add a script tag, not a javascript code. For this purpose, you should modify footer.php file in the theme and add your tracking code directly before </ body> tag.