If there is no God, what is the meaning and purpose of life even existing?

There is no reason. Get over it. We are here because of amino acids mixed together, and then billions of years of evolution. That is your reason.

i think a life would have much more purpose if that person was living just to get the most out of life without a deity, rather than having a deity give purpose to their life

We are each our own gods. We create our own meanings.

Meaning or purpose of life is whatever the individual wants it to be.

The meaning of life is to live...quite literally.

" it still does not explain WHY life formed" There is no innate "reason" for life, there simply is life. Each of us determines our own meaning of what the world around us exists for.

Technically To reproduce

The universe is thought to be open; it will expand forever, becoming too cold to support life. Life cannot have an enduring purpose. The Big Bang theory doesn't address the issue of how life formed. Abiogenesis does. "There is a purpose for everything." Prove it. Seems to me a lot of the universe is a waste of space and energy.

The purpose of evolution isn't to prove the meaning of life, just the origin. Nothing more. And the purpose of the big bang is show why there is stuff and why there is space for the stuff. Again, it also was never meant to show why there is life. This is like asking why the story of the burning bush doesn't explain why there is life. It's not supposed to. Oh i see. I admit i was confused by your first question. Thought you were looking for a meaning to life, not meaning in why there is life. Alright, amino acids and chemical reactions. Chemical reactions are always occurring in nearly everything. Inside of you, in the ocean, in the dirt next to your front door. Why do they occur? So atoms will gain stability. For example, oxygen will react with carbon because the product, carbon dioxide, has more chemical stability - in other words, each atom shares its electrons to give the other atom(s) in the molecule an electron arrangement of more stability than the one before. They can't help themselves :p Not every element is compatible with every other element. There are only so many possibilities in combining atoms to make molecules, such as amino acids. When all the elements that make up an amino acid (Hydrogen, Carbon, Oxygen, Sulfur, and Nitrogen - none of which are rare at all), which were very abundant in the atmosphere of early earth, and are still there today, but in smaller amounts, then inevitably, amino acids will form. It's just a matter of time, and there was plenty of that.