You can change your listing whenever you like. Log in, open your listing to edit it, make your changes, and save. You can update your photos, videos, working hours, services, and contact details, so it is easy to keep everything current.
Photos matter more than anything else here, because good ones are the single biggest reason couples reach out. Videos are added as links, for example from YouTube, rather than uploaded straight to the site. How many you can add depends on your plan: Single Basic and Single Pro allow 25 photos and 10 video links, Team Starter allows 15 photos, Team Plus allows 25 photos and 10 video links, and Team Premium allows 40 photos.
A few things worth doing: pick your clearest, brightest photos, show a range of real weddings rather than the same look over and over, and put your strongest image first, since that is the one couples see in search. Refresh it after a great wedding, and always keep your phone number right so couples can actually reach you.