How do I link my email account to Libre Office so I can send emails directly from my newly created documents?
If your are talking about File -> Send -> Email Document then you dont link your email account but your default email application, which is set in Tools -> Options -> Internet -> Email, which allows to start your email program given in the setting and set the current file as an attachment. No user information to be managed by LibreOffice.
Please also see this FAQ
That advice is applicable only to Unix-like systems: if you are using Windows you simply need to have a suitable email client, such as Thunderbird, set as the default mail client. Note that using web-based email client is not possible.