Is there a way to get a signup form to populate a list? If that isn't possible, how do I automate an

Is there a way to get a signup form to populate a list? If that isn't possible, I'm trying to send a link out on SM to build my list by offering a series of informational emails. Think of it as a 5-day challenge. So I want people to sign up and start getting these emails. I created a list and a landing page with a signup form. Can someone help me link them? Or is there a better way to automate this? Thanks!