Is it the *owner* you are worried about or did you create the tables in the postgres database instead of creating a new database and using that one?
If the database is correct but not the owner you can just use "grant/revoke" to update privileges as appropriate.
If you created your tables in the postgres database, you have a few options. One is to dump the postgres database using the --no-owner option then create your desired database and restore, as your desired correct new owner, the dump into your new database.
Another option is to use the "alter database" command to rename postgres to your desired new name and to change the ownership of the newly renamed database as desired. You should then recreate the postgres database from template1.
Finally, you can create the new database using postgres as the template database. You will still need to alter the newly created database to set the ownership and, potentially, grant privileges. More on creating database from templates is here: