You can change the name of an item once it's been created. You can do this either:
Looking for the legacy help documentation? You can find that here.
From in the item
1. From within the item, click on the item name at the top of the page or the pencil that appears when you hover.
2. Re-name the item and click anywhere else to save the changes. The changes will be immediately reflected on the item.
In bulk from the Content tab
1. Inside the project, head to the Content tab.
2. Click the 'Re-order Items' button.
3. Click the item name you want to re-name and edit it directly. Do this for all items you need to re-name.
4. Hit 'Save changes' when you're done.
All changes will be applied straight away.