As far as I know Community Specialists are Apple employees whose primary duty is to look for posts that linger unanswered and then only seem to post links to published Apple support documents that may be applicable to the problem. The rest of us are volunteers and handle a lot more posts.
You would have to look at the Apple Jobs posting pages to see if there is a lower age cutoff for employment but I suspect it is more than 15.
One of our more helpful and active posters here not a CS and is, as I recall, still in high school; he has a higher level rating than I, and I've been doing this since about 2000--probably the year of your birth! You can make real contributions by posting as yourself and providing helpful answers. Eventually you will level up like so many of the old-timers here, and will see more "action" than the Community Specialists.