The longest lived stars, red dwards, will most likely simply fizzle out like a hot plate you turned off. It is unlikely we will ever observe such an event.

Even our Sun doesn't go Supernova, it just blows up a bit and discards it's outer layers, forming a white dwarf.

The stars that go Supernova are much more massive (around 3 times, IIRC) and have orders of magnitude shorter lifetimes (measured in only a few hundred million years at best).

Galaxies can undergo bursts of star formation which are accompanied by lots of supernovae, because supernovae come from massive stars which don't live for very long. The universe was most active in star formation and supernovae about 10 billion years ago.

The lifespans of stars vary by orders of magnitude. The sun is about 4.5 billion years old and is not massive enough to ever be a supernova. Betelgeuse, a candidate to go supernova 'soon' is only about 10 million years old.