Title and tagline
Your title is your name, or your business name. Your tagline is the short line under it — the one that tells somebody what you do before they read anything else.
Treat the tagline as the first of the three sentences: what you fix.
The footer
Your footer carries a small "made with Yoursellf" credit. It links back here and carries your referral code, so if somebody who sees your page signs up, that is attributed to you.
It is on by default and it can be turned off from the footer settings.
Payments
If you have not connected Stripe yet, the settings will tell you so and offer the way in. Until that is done, offers on your page cannot be bought — a visitor sees the price but there is nowhere for the money to go.