If you want to delete a complete album AND all the pictures inside, please follow the steps below:
1. Go to your profile
2. Click on Albums below your main profile picture
3. Click on Albums again below the first one you clicked
4. Select the album you want to delete
5. Once you are inside the album, look to the far right for 3 dots on top of each other - click them
6. Select Delete Album
7. Confirm the delete.
Thats it - you have now deleted your album AND all the photos inside it.