Passions are activities that bring us joy and can be sustained over a long time. We feel joyful doing these activities because they get us into a "flow state" or "in the zone", where you are fully absorbed, chugging away almost effortlessly. You get there when you achieve a balance between the level of challenge and ability that lets you perform without interruptions and produce desirable results, which in turn motivate you and provide you resources to do more of the activity and improve your ability.
People who have and pursue passions live more fulfilled, exciting, and joyful lives, which is why it's worthwhile to nurture a few different passions. I say nurture and not just "find" because we don't develop passions by default - we aren't born with them and we don't simply find them. I say nurture a few passions and not just one because it's good to diversify for variety and just in case you lose the ability or interest to pursue some passions.
There are two main requirements for developing a passion. The first is picking an activity that has the potential to become a passion. And the second is getting over the beginner's hump.
Picking an activity is important because not all activities have the same potential to become passions. Some activities may have a low flow state as they need a large team, coordination, or a lot of interruptions. Some activities may not have higher states of challenge or rewards. Some activities are more suitable for your physical and mental aptitude, environment, resources, and preferences. Creating (art, music, programming, writing, etc.) and sports seem like the most common domains of flow-full activities.
When you start out on a new activity, you are challenged by the beginner's hump. Your ability is low - your activity is constantly interrupted by needing to look up instructions, get help, tune your tools, make corrections, etc. The substance and quality of your results are also not inspiring enough to keep you going. You may hit similar plateaus and humps at later stages. Deep curiosity or desire, perseverance, good coaches, and peers can help you get over these humps.
When you find an activity that has passion potential and get over the beginner's hump, congratulations - you have given yourself a wonderful gift of a lifetime of joyful flow states!