When coming to image editors, there are so many available to Ubuntu. An image editor such as Gimp can be too much for simple image edits such as cropping. we need a lightweight solution with a simpler UI.
The most simple way to make basic image edits is to use Shotwell. Shotwell comes preloaded with Ubuntu and is a good software for image management. Right-click on your image to edit and open it with Shotwell software.
The user interface of Shotwell is easy to use.
As you see in the screenshot, you can use basic image editings such as rotation, cropping, straightening, red-eye correction, color adjustment, and image enhancement with the Shotwell Viewer. Making Shotwell Viewer the default app for image viewing can make your actions faster.