Hello!
A star is a large, spherical burning ball of gas located in outer space. They are made of hot gasses and plasma.
They are born in a nebula which is a large cluster of stardust. Many stars perform nuclear fusion, where hydrogen nuclei combine to create helium. This provides stars energy to burn and prosper for billions of years.
When a star is dying it will begin to lose its power. It will eventually explode in an enormous supernova. This has a chance of creating a black hole. Usually the remnants of the supernova will form another nebula, therefore continuing the cycle of a star.
I hope this helps!