
For brightness, contrast and gamma, click Color Adjustments. You probably don't want to use Auto Levels and Brightness together, but it's possible.
Drag the red cursor in the effects window so preview shows the content. Changing any setting is immediately reflected in the preview window.
To save the correction you have made, click the 'folder'
in the effects toolbar. Name it.
It will appear as just another effect icon at the bottom of the effects screen, to be applied to other clips.