You can manage your account at the top-right corner of the interface. Click on your user avatar then.
The pop-up with Account settings will appear:
Here you can change your Names, email address, password, as well as your Purchases if you have made any. On this screen, you can delete your account.
Be careful: If you delete your account, All your files saved in the Cloud will be permanently deleted. All Corel Vector Discussion comments will be deleted. All purchased items and subscriptions.
Note: The names you fill here will be used as an Author inside the exported PDFs.