First experience with Kontakt 5

Before I go into buying my first sample library and official Kontakt, I have the free trial + the factory selection for now, just so I can get used to it before I actually begin working on this. For the Midi inputs, I have the first one set to Port A, and rest off; for outputs, I have all 'off'. For audio, I don't know which driver to choose. If I choose ASIO, I can hear the sound of the samples, but then I can't hear anything else that's happening on my computer at that moment (I can't hear the Youtube sound). Or vice versa, if I have it as WASAPI, I can hear all the sound that's happening on my computer, but then I don't hear any sound of the samples. Not sure if this is normal. Also, I have MOX8, and everytime I try to play the samples from the keyboard , I hear two sounds: the sample sound and the actual sound that MOX8 is making (because MOX8 is originally a synthesizer that can also function as a midi controller), so I'm not sure how to not hear the sound that is coming from my synthesizer itself, but rather hear just the sample sound.

Help appreciated,

 

Turn the volume all the way down on your MOX8?

Which ASIO drivers are you using, what's your audio interface?

 

If I turn the volume down, the sample sound also disappears, but I found a way to turn off the synthesizer sound so that part is good

I don't know what ASIO driver I have nor do I know how to check. And I have Xonar Essense STX, but I don't currently use it.