It's great that you're thinking ahead and planning for your time in college. I think you're on step ahead. You're right that college can be overwhelming and stressful at times, but it's also a new phase in your life that will bring unforgettable experiences, if you go about it the right way.
First and foremost, learn to manage your time and be organized, if you aren't already. I think being disciplined with your time and learning to schedule all your activities, goes a long a way in helping to reduce your stress, and be more efficient, overall.
Also, I'm a major proponent of getting a good night's sleep. Getting enough sleep will have a positive impact in your overall well-being and will allow you to be more effective in your day-to-day activities. Avoid all-nighters, if at all possible.
You can try to get involved in extracurricular clubs and activities that will allow you to socialize with other students and make friends. Having a social network (and not just online) goes a long way in improving your sense of well-being. Physical activity is also beneficial in keeping you healthy and energized.
If you still feel the stress coming on, you can manage it by practicing yoga or meditation, going for a walk. Anything that will be relaxing, and healthy. I wish you the best of luck and much success in your college years!