I've never believed in god. I went to church as a young child, then not for a long time, then again as a high schooler before stopping altogether some time in 12th grade (all of this being in an anglican church, which is really like church "lite" with tea and cookies afterward). When you don't have a faith, you end up having to confront mortality without the guise of an afterlife pretty quickly, so i didn't necessarily have a singular experience that helped me come to grips with death.

The way I see it, the days you have on this planet are of an unknown number that is continually ticking down to zero. You might die tomorrow, you might die when you're 111, but no one can know. Since you have that Unknown, the only thing you can do with your life is make sure that the things you spend your time doing are worthwhile to you. I don't mean that in a selfish, "fuck everyone I'm going to do what I want" sort of way, I mean that in a " I think this cause is worthwhile so I donate my time to this charity" or " I like to drive and my friend needs to do errands. I'll drive my friend around to do his errands", or "Music is my passion, so I'm going to make it the focus of my life". In essence, live your life in a way that if you died tomorrow, you would think "There's more I wanted to do, but I think I did alright", or "I'm okay with this".

Make sure the people you care for know it, tell your parents you love them (because you do have to love them, even if you don't necessarily like them), and, as they say in those inspirational coming-out speeches, "live your truth"

Dying is uninteresting, everyone does it, and everyone is alone and afraid when it happens. It's how you use the time between your birth and your death that makes any lick of difference to anyone.