Planners and your account
Both are on your Profile under Account. Download my data gives you everything as one file. Delete my account locks it straight away and removes it for good after thirty days, and you can cancel within that time.
Open your Profile from the account menu and go to the Account tab.
Tap Download my data. It comes as a single file with your plan, your guests, your saved vendors and your page. Enquiries you sent to vendors are not in it, because they are the vendor's business record as well as yours.
If a planner is working in your wedding, tell them first. Their access ends with the account.