How did Christianity start and why do people believe in it?

Not meaning to be disrespectful to any Christians out there but I've never believed in Jesus or god but now I'm just wondering how did it start and why do people believe in it? Because for me I've just always thought its mostly just a "trust me" type of thing but now I'm actually curious as I've really never researched it. And it just gets really confusing as there's so many claims that seem to conflict with each other, like people say there's this and that then people saying there isn't. Really just wanna know more since it seems interesting.