Question

How does sun emit it's own light and temperature

Answer 1

It's a celestial body which can emit its own light

Answer 2

There are reactions taking place on the sun's surface, wherein 600 million tons of hydrogen, are converted into helium. This reaction gives out immense heat and light. The amount of heat and light producd is so much, that we, at Earth which is 149.6 million km away, can feel and see it.