I will explain. Exposure level is a setting that the camera uses to determine what is too dark and what is too bright in terms of what it is recording. This is important because there is a lot MORE light around on a sunny day with very-reflective snow and the very-bright sky everywhere versus a day at the indoor rock climbing gym where the halogen lights are 40 ft away from you.
The camera has to be able to record well enough in both settings even though the camera sensor has a limited range of brightness. The camera decides what the correct brightness is by metering what it sees.
You can tell the camera to look at everything in the field-of-view and then make its decision as to the proper brightness (evaluative metering), or you can tell the camera to only look at what it is focused on in the middle to determine the proper brightness (spot metering).
Using the wrong mode can cause different problems. Blown out highlights means that the camera was metering off of a subject that did not reflect much light (like a shadow), compared to the surroundings.
Very high contrast an really muddy dark areas with no definition means that the camera was metering off of a subject that was really bright compared to other subjects, so everything else looks very dark with no detail.
Proper cameras give you the ability to adjust problems with exposure... but it can be tricky to do with consumer-level crap like the GoPro which immediately encodes and compresses the video into formats that are not well suited for editing.
You can try using fancy video editing programs like Vegas or Premiere to correct the problem, but you may have limited success depending on how blown out everything is.
White blaance is something different. White balance is for adjusting the color of how everything appears based on what color the lighting is when you are recording. (for example, the lights in your living room and bedroom are 'warm' yellow lights, while the lights in an office or classroom are closer to white).