There is no single answer. You search for and decide what makes life meaningful for you. There are a lot of great answers in this thread, I particularly like i

There is no single answer. You search for and decide what makes life meaningful for you. There are a lot of great answers in this thread, I particularly like inphovore and Waterluvian's, but yours might be different. You need some minimal things to find happiness, enough food, shelter, and health. Sadly, in the US, we don't get those things, but there are places that can help you. You may need to move. You may need to live with family, friends, or strangers to get started on your journey. But, you must start your journey and only you can do it. Read quotes from Mark Twain, The Obstacle is the Way, and The Conquest of Happiness. Do something that brings you joy and embrace it -- this is particular hard for me. I'm still searching after 50 years.