On a Mac, you have several options for editing photos easily. Some popular apps you can use include:

  1. Preview: Preview is the default macOS app for viewing and editing images. You can crop, resize, adjust brightness and contrast, and apply basic filters.

  2. Photos: Apple's Photos app offers basic editing features. You can adjust brightness, contrast, saturation, and apply filters. It is integrated with iCloud, making it easy to sync your changes across all Apple devices.

  3. Adobe Lightroom: Lightroom is an advanced photo editing app that provides many advanced adjustment features but is intuitive enough for beginners. You can experiment with color balancing, exposure correction, and other advanced editing tools.

  4. GIMP: Although more advanced, GIMP (GNU Image Manipulation Program) offers a wide range of features similar to Photoshop and is free. It may take some time to get used to the interface, but it is powerful.

  5. Affinity Photo: A professional photo editing app that is less expensive than Photoshop but offers many of its features. It is suitable for both beginners and professionals.

  6. Pixelmator: Pixelmator is a user-friendly image editing app that provides a wide range of photo editing tools. It is less expensive than some of the more advanced options.

Choose the app based on your needs and the level of complexity you desire. If you are starting out and just want to make basic adjustments, Preview or Photos may be sufficient choices. If you want to explore more advanced options, you can opt for Lightroom, Affinity Photo, or other similar apps.