I would like to start doing commentaries for youtube but i dont know what software to use. i have a i7 6700 and a strix gtx970. it would be nice to have a audio software that could have 3 different audio tracks.(one for game sound, my voice, and then the game chat.
Nvidia might help you out with shadowplay. Otherwise try OBS, it can capture video and audio. For more audio settings and stuff you might wanna take a look at audacity.
I use a combination of OBS, Voicemeeter, and VB-Cable. Voicemeeter is a virtual mixer and VB-Cable allows you to set up multiple sources as virtual audio devices. Using those I'm able to separate system audio, my mic input, and whatever voice chat I'm using (mostly Google Hangouts, but also works with Skype or anything that allows you to configure audio in and output). You can then configure OBS for multiple audio streams. Voicemeeter allows you to adjust the gain of each source. Doing it this way allows you to have all three streams already embedded in the video recording (and if you've adjusted them correctly, at more normalized volume levels), making it much easier to manage in post. There are a bunch of tutorials at the bottom of the Voicemeeter page. It definitely takes some work to set up, but it's worth it.