What can I learn/know right now in 29 minutes that will be useful for the rest of my life?

In 29 minutes? Less than 29 minutes to “know”, a Billion dollar education to eventually learn, shoved up your ass a nickel at a time:

You will die at a time and place currently unknown.

You will experience both joy and grief in your life

Don't smoke.

Don't have sex with anyone you can't marry.

What you are doing for work at age 40 you will likely do for the rest of your life.

Treat others as you want to be treated. Karma is a bitch.

Compassion is the ultimate virtue.

Don't look down on a person unless you're bending over to help them up

Don't judge a person until you have walked in their shoes.

Honor thine own self first-acting incongruous to your personhood will scar you, and block future self fulfillment.