Hello @JohnT1025 ,
You don't link to lists, you link to sign-up forms that are connected to that list. If the sign-up form is one you've coded to your website, you'd just link to the URL for that webpage of your site. If the form is a landing page, you'd use the URL we generate for it.
For instructions on creating coded forms:
See also:
Inserting Text links into an email
Inserting Image links into an email
Inserting Button links into an email