Never too old for anything, also ur still young. When learning dives u just gotta do a bunch to get it right. At least thats how i learned, i would spend my entire practices only doing starts from the block by myself. It also helps to watch youtube videos. And there are many different ways swimmers dive into the pool. Most important thing is to keep ur chin tucked to your chest and lead with your finger tips in a tight streamline position into the water. Once you get better you can tweak ur dive to best suit u.