You need to stop seeing yourself as "more the endurance type of runner."
Shift your mindset to something more along the lines of "I am a fast runner with good endurance."
You also can change your mindset when you are at practice. Stop thinking of running as an effort, and start thinking about it as a skill. Speedwork is not just running as hard as you can, you are practicing running fast. For race-pace/tempo/threshold type workouts, you are practicing staying as relaxed and smooth as possible while running at those speeds.
If you're looking for specific exercises, you can't go wrong with squats and pull-ups. I have seen a lot of runners who see themselves as "more the endurance type" who are actually proud of their lack of upper body strength. Don't be one of those dweebs. (Not saying that people without upper body strength are necessarily dweebs, but if someone your age doesn't have it and doesn't care, something is wrong with them.)