Maybe start to know what our Creator is like, his attribute, and what our Creator want us to do. If you don't trust that there is an Creator, you just have to find out whether if Bible is our Creator's word or not, and talk about truth or not(compare Bible with some science and history), because all things about Creator can be found from Bible.

I think this is a good start, because of course our Creator is the person with most wisdom. And simply, our Creator is the one who create us, so we must know why he create us to have a meaningful life.