Hello @Phil105,
You can delete the incomplete account but you'll have to go manually add the listing to the more complete account. There's no way to copy information from one to the other. You can make it a bit easier on yourself by first manually copying any text, like the description and house rules, to a temporary document for later pasting when adding the listing to your more complete account.
To delete your incomplete account log in to it on a computer. then click on your profile photo and select "Account settings" and then "Settings" on the left. Then select "Cancel my account".
The article below explains it and the consequences.
How do I cancel my account?
Then log in to the more complete account which you wish to keep and add your listing as you did before.
Steve.