Odds are, if you are reading this now you probably already feel purpose. Usually people with a passion or hobby do feel a sense of importance. I'm no genius, I haven't researched or come up with this notion on my own. It's been my personal experience, philosophy conversations, books, etc. where I realized that this is a shared idea.
Having a daily routine where you incorporate at least one daily goal will set your mind on a forward path, and will eventually bring hope and excitement for the next day. The brilliant Dr. Jordan Peterson goes into more depth about this and how your brain & physiology reacts to routine & purpose in his book 12 Rules for Life. (Not an affiliate, I'm just a fan)
My advice is to start small if you can't think of something that you'd be passionate about or if you feel like you don't know where to start. A few years ago I began to plant mammoth sunflower seeds which was sparked by my Dad when he planted them one year and produced huge beautiful sunflowers. I've planted the seeds from my successful plants every year since and it really makes me happy. From seeing the first little seedling popping through the soil to seeing the huge bright orange petals unfurl and finally to cultivating the hundreds of seed from each plant; it's such a satisfying experience.
If you have someone in your life that you think could use some purpose, maybe give them some seeds as a gift with instructions, and encourage them to plant them. Perhaps you could join in and compare progress every week. What do you have to lose?