You will get the Now Hub, a router (sic) sent to you.
But Now aren’t going to send you a phone. If you want one, and you haven’t already got one, you will need to buy it yourself.
Set a Payment PIN on your account so that no-one but you can buy memberships on it. Check your bank accounts monthly for any other unexpected payments to Now. That way you can at least nip them in the bud, while you and Now figure out whose fault they are.