Go to the festivals page, find your area and sign up to take part there. You will get a confirmation email from your local organiser.
See your local festivals page for details. Sometimes local festival organisers ask for a small amount of money to cover costs or raise money for charity.
Absolutely, in fact higher up windows are easier to view from the street.
You can, but without your address on the map, people won’t know to come and see your window. By signing up through this website you are helping your organiser to gauge interest. Your name or email will not be shown to your organiser. You are signing up so you can go on the map.
You can email your organiser and ask them to put you on manually if you do not want to register, but want your house on the map. The disadvantage of this is you will not get updates from your organiser if they are planning anything around the festival or things change.