Where do I start finding my own evidence

I have so many doubts of my religion but also a bunch of questions and I see all these people who say they’ve broken down their beliefs but I dont know where to start so I can stop relying on other people and what they believe. Where do I start if I wanna research Christianity and other religions to see what I believe? Im not even an adult and I’m thinking way to much about death and religion every day I’d just like to be sure.