O have used Windows Movie Maker, iMovie, Sony Vegas, FCP, and Premiere Pro. I currently use Premiere Pro as I found it to be my favorite. These programs are as easy to use as you make them, meaning that you can do basic editing in Premiere Pro with just a little time on youtube learning to setup your project and how to import clips and export your project.
If you are serious about video editing, you should go with a more powerful program such as FCP or Premiere Pro.
I am 100% self taught. I learned all of what I know about video editing from youtube. You have to be motivated to do this, as it will take hours to learn 30 seconds worth of advanced techniques.
GoPro wise, if it is a Hero 1 and shot in low light it will be very grainy (noise).