This is my first recording using an audio interface and a DAW. I found it kind of challenging at first. But it is such a fun way to play/record. If anyone has questions I'll gladly share the knowledge I've gained so far.
That button is a kill-switch. I installed it myself. It mutes the guitar signal. They are really fun to use, and you can get pretty creative with them. The best example of a killswitch is probably Buckethead(another one of my favourite guitar players).