It depends what you want in the drone and what is of the utmost importance. Is it portability and size? Is it image/video quality? Is it distance? Is it flight time? Is money a big factor?
I own many different DJI drones. For me IF I was to own only one drone it would be the Mavic. Its a good "jack of all trades" drone. Its small enough but not the smallest. its good in higher winds but not as good as the Phantom 4, it takes good quality images/videos, better than the Spark but not as good as the Phantom 4.
Both the Spark and Mavic have their pros and cons. You just need to decide what you want in a drone.
While I'm always as advocate of starting with a "GPS-less" drone to learn the basics of drone flying, you don't need to. I've got friends whose first drones were Mavics and Phantom 4s who have had no issue. Key is they read all they could on drones and their particular drone, they watched youtube videos, they took their time learning and not forcing long distant flights or just throwing it in the air right out of the box. I do have one noob friend who did that and that was months ago. He's still flying crash-free...