Computer Science and Premed are both excellent career paths; challenging but greatly rewarding. I will say this, one's college degree does not dictate the path you may take (I majored in and completed graduate studies in chemistry but am doing software engineering now). I will also say that I am aware of people obtaining multiple degrees before going into medical school and still yet people moving on to do M.D. Ph.D.'s and focusing medical research (which could include computer modeling!).
I would say it doesn't hurt to know some CS because we live in an increasingly interconnected world via the internet and will continue to do so for the foreseeable future. CS as a field will definitely teach you critical thinking skills allowing with problem solving which are always good to have. That said, I would also be sure to focus heavily on biology, as from my experience CS and biology sometimes felt disjointed (except in bio-molecular computer modeling).
I think to at least get a taste of what people who do CS do during their careers (most likely programming) you can check out websites like:
Additionally, you can watch lectures for free from MITs introduction to computer science course:
Christopher recommends the following next steps:
- Check out some computer science lectures
- Try out some coding