How do I change a category name?
Go to Bookkeeping > Categories > select category > Edit name.
The category 'Uncategorised' cannot be renamed.
How do I delete a category?
Go to Bookkeeping > Income & Expenses > select category > Delete.
You can only delete categories that do not contain transactions, to prevent bookkeeping data from being spoiled. To delete a category that contains transactions, move those transactions to a different category first.