Paul:

I completely agree with Thomas recommendations and will only add a couple of thoughts because I have coached a lot of juniors (<20years) in my coaching career.

First thing is to NOT try to train like an adult. Don't copy what you see the top climbers or runners (who are 30 years old) doing in their training. Your body is not ready for those kinds of loads yet. You've got at least 8 years before you reach full physical maturity.

It's important that you use these years wisely. You can do this by developing good technical skills, these teenage years is a time when your body is the most plastic ad will learn new skills the fastest. This will be especially true for rock climbing. You will develop adequate strength just through your climbing itself and do not need to get crazy with specific climbing strength yet.

For the running end of things you build this slowly as well in these years. Building strong connective tissue during these years should be your goal. Do this by gradually building up running volume and vertical. But DO NOT go out and run with much stronger and older runners trying to keep up with them.

I hope this helps.
Scott