Question

how does a stars life begin

Answer 1

All stars form from two key factors: the presence of material which can condense into a solid mass, and gravity, the force which results in the compaction of the material.

New stars are essentially formed from old stars which have exploded or died out and have become stardust. When this stardust accretes (becomes condensed) again, the temperature increases, and when the proper considtions are present, a nuclear "furnace" can be the result. In the furnaces within stars, atoms are fused together. Fusion is the process where, under extreme heat and temperature, atoms combine and give off byproducts. This process creates the heat, light, and other particle emissions we experience from our own Sun, which is 93 million miles away from Earth, and considered to be a "main sequence" or somewhat "typical" star, at least as to here in our Milky Way Galaxy, which is thought to contain hundreds of millions of stars.

Modern scientists use the Hubble Space Telescope, and other special science satellites, to look at areas in space where they know or suspect new stars are forming. In these places, the raw materials (star dust and gravity) are present. Scientists can actually observe stellar "nurseries" at work, and they are continuously learning more about exactly how stars form.