How do I sign in as a host?

With the email and password you signed up with, or with Google if you linked it — guests never sign in at all.

Hosts sign in with an email address and password, or with Google. You can link both to the same account and use whichever is convenient.

If you signed up with Google you will not have a password to start with. Use the “Forgot Password” link on the sign-in page to set one, and after that either route works.