I think before worrying too much about editing software, it might be the effort (which can be fun with the correct mindset), to do a bunch of test recording. By that I mean, find the kind of scene you like, and then record it a hundred and forty eight thousand times (roughly), but keep changing the camera settings. For me, that gave me a much more useful comprehension of how the system behaves, and my success and failure at getting good shots is becoming less and less random. With photos, we can cheat by doing 'auto exposure bracketing' to capture extreme ranges of bright and dark, but with video we are locked down within a small contrast, and so getting the exposure dead on when shooting is critical.
I strongly recommend this approach rather than an alternative approach of trying to get an editor to fix a 'bad' shot. As mentioned, the sensor in this teeny tiny little camera has its limits, and so it is more difficult to get a good shot than a camcorder of a quarter the Mavic's price tag, and impossible to do some shots at all.
Also, there is an editor built into the DJI Go app, just saying.