GoPro Editing Software??

[JJ]

Are you using a MAC or a PC?

Either way, use the GoPro software to edit and convert your footage.
Then export it in a .mov or other format. Be sure to set the settings for the highest resolution when exporting.
If you're using a MAC, Final Cut Pro X is an awesome program to create your movie, as is iMovie.
On a PC, you have many choices ranging from Adobe to Sony Vega, etc.

YouTube and similar sites have copyright protections.
If you upload anything that has copyright protection, your video will be subject to various restrictions.
I once uploaded a video of some little league baseball stuff that I edited.
The song I used (We are the Champions by Queen) was/is copyrighted.
Immediately, I got a message that said my video was blocked in some countries, including Germany. Go figure!
I just left it there since I didn't care about the restriction.

If you don't want to deal with copyright stuff, you can purchase online copyright-free music, or use YouTube's music that has already been cleared.
Depending on how much time and effort you want to put into it, you can also make your own tunes with Garageband (MAC) or other apps.
Many video editing software also have royalty free or copyright free music you can use.
I know iMovie and Final Cut Pro have a bunch.

JMHO. Hope that helps. Good luck and have fun.

-JJ-