It is not possible to rename main categories. However, you are able to rename Wallet's default subcategories. To rename default subcategories, please follow the instructions below:
1. Click on the Settings tab in the menu bar.
2. In the Settings menu that appears, click on Categories.
3. Select the main Category to see the default subcategories.
4. Click on the pencil icon next to the name of the default category.
5. Enter the new name of the subcategory and click OK to save.