Start with researching/searching for using the "Histogram" as well as the "over-exposure warning/zebra stripes"...Those two tools that are part of the settings in the camera will give you a good base to build on.
Best to get familiar with how to optimize your original image while shooting before trying to learn the post-editing (lightroom/photoshop, etc)
I always suggest that a "new" user should take some time and just sit the drone on a bench/seat and just take some photos at a static scene and then mess with the settings to see what happens and how it affects the image. That practice will help when you are flying and need to make adjustments.
As most are stating, Starting off in "auto" will achieve some nice results...most get out of auto because of the constant changes of the lighting, etc that flying a drone will cause and the automatic adjustments are visible in the finished video/image.
This little guide from DJI has some basic info, also.
Online shopping for a great selection of at the official DJI Online Store.
store.dji.com
And the Go 4 manual has some better explanations of the settings
Online shopping for a great selection of at the official DJI Online Store.
store.dji.com