If the sun went nova it would destroy every known planet in the Solar System.
But the sun is not massive enough to go nova. In 4-5 billion years the Hydrogen fuel in the sun's core will have all been converted to helium. The core will contract and heat up, and upon reaching 100 million degrees Celsius, Helium fusion will begin. The outer layers of the sun will expand to about Earth's orbit, becoming a red giant, but the loss of mass early in this phase will mean that Earth will probably move to a wider orbit, and not be engulfed as Mercury would be and Venus would probably be. Although the expansion cools the sun somewhat and makes it emit redder light, the heat emitted will be much higher than today, and despite being further out, Earth's oceans will boil away, and become like Venus now, until the atmosphere, too, is lost to space.
The red giant phase will be short lived, and eventually the outer layers will puff away due to thermal pulsations, forming a planetary nebula, leaving the core a tiny white dwarf that will slowly cool and dim.
There will be no nova here, but the outlook for Earth is not good. Fortunately, we'll all be extinct long before the red giant phase.