Does anyone have any suggestions?

You could join an online writing group. 'Critters' is a good one, I was a part of it for quite a while. Also, the forum 'Develop My Skills' is basically like a writing group, and I'm also a part of that. It's very good. As for actual real world writing groups, they can be harder to find. I'm a part of my school writing group, but since there are all of four members (including myself and the teacher who runs it) it's pretty exclusive. Your age might be a concern; no matter how talented you are at 12, at 18 you will be much more talented.