you obviously need help but won’t google anything, so here goes. Now you can stop claiming that nuclear fusion happens much later? How could it be later when it’s required to form the star from dust and gases
Nuclear fusion
After millions of years, immense pressures and temperatures in the star’s core squeeze the nuclei of hydrogen atoms together to form helium, a process called nuclear fusion. Nuclear fusion releases energy, which heats the star and prevents it from further collapsing under the force of gravity.