How do you connect with your past life?

There is no such thing. No future life either. This is it. You don't know any such thing. You may wish it but it does not make it so.

I'm not sure maybe in your dreams and try to connect with your spirit or pray to God about it.

it's not possible

you can speak to a psychic medium that may be able to read your past life. Google search "past life reading". I'm sure there's tons of people who will take your money to make something up for you. :p

You can relate to the past through photos, diaries, friendships between friends, achievements made now, and so on. We need to look back often to see what we have done before, and then to see what we are doing now and what we need to do in the future. There is an old saying in China: "Never forget why you started, and your mission can be accomplished." and I hope it will help you.