It all depends on how hard you work towards that goal. Are you good at science? A lot of your course work will be heavy on chemistry, biology, and physiology. You'll also have to be able to do well in calculus. If you spend extra time on the subjects that you struggle with, you should do fine. You don't need to get straight A's but it would be nice to help your GPA towards admissions. If they see that you took difficult classes and maintained a 3.7+ average than you should be on the right track.
Also, MCAT is a big determinate. I'm not a great test taker (I get nervous) so it's best to start studying early. I'm in my second year of undergraduate studies and I'm studying general studies for the MCAT just so I can be fully prepared.
There are a lot of extracurricular and projects that you can do outside of your studies that will look good on your application. Try volunteer work or getting an internship; not only will this help you understand the field but it will show that you're a hard working and ambitious individual.