Which is the nearest star to us that could go supernova? What would that event look like from earth?
The closest star to us which could go super nova is Pegasi.
If you are worried about our being affected by a super nova don't. At star going super nova would have to be within 75 light years away and Pegasi is 150 light years away. The next closest is Spica at 260 light years away.
Our star neighborhood is like what the middle of Kansas is to New York City.
A super nova, if visible, will look like a particularly bright star.