A star is first formed from an interaction of dust and gas that eventually make the star giving it it's core and source of shining light.
1st stage of a star
Once that has been made the core will begin to combine hydrogen atoms to make helium which is called nuclear fusion which powers the star to keep living and shining. What happens next to a star after that depends how big the star is to begin with
2nd stage of a star
Towards the end of a star le cycle depending on the size of a star whether it's big or small it. will come to an end. If the star is small the nuclear fusion will come to a halt and the star will become a white dwarf meaning it stopped producing energy and will eventually burn t like a candle to finally became a hack dart and be completely forgotten in space it's a big star the star will coins to expand eating heavier elements that way gravity wert stop it from growing but eventually it grow to big and explode which is called a supernova and that be the end of the biggest star