Our Privacy Policy explains what we hold and why. In short: what you enter, what you upload, and the records of bookings you're part of.
You can ask us for a copy of your personal data at any time and we'll provide it. You can also ask us to correct anything that's wrong.
Bookings, invoices and statements are the business records of the agencies and venues involved. Those stay with them even after you leave, because they need them for their own accounts and tax. Your personal profile is a different thing and goes when you go.
To delete your account entirely, see Deleting your account.