The next layer away from the core is the middle layer of the radiation zone then comes the outer layer or convection zone which helps move heat from the core to the surface.
The closest star beside the sun is Proxima Centauir 4.3 light years away a light year is the distance light travels in a year about 9.6 trillon km (6 trillion mi).
The suns diameter is 865,000mi 109 times that of the earth and it is over 93,000,000mi away from earth its light traveling at 300,000 eight minutes to reach earth.