Hi brandi, I think what you are looking for here is how to send an email to your subscriber after they confirm their subscriptions after signing up to your landing page?
You have two options, if you are paid plan subscribers you can create rule automation to add them to a tag after they sign up to your landing page. From there you can use that tag to send a broadcast email.
The next option is to create visual automation, when they sign up to the landing page they can be added to a series of emails.
The links below are for your reference: