I have found my first semester to be a drastic change from high school, but I learned how to make sure I got the support I needed and could not really imagine the semester having gone any better. I believe the most under-emphasized resource available to students in college are office hours, whether they are of your professor or Teacher's Assistant. Office hours are a time where you get one-on-one assistance and guidance through whatever you need- it doesn't even necessarily have to pertain to the specific class you are in. They are thoroughly happen to meet students showing an interest in learning, and I know many people who do not take advantage of this because it may seem intimidating at first. Know this is under your own jurisdiction, as well as any homework or other assignment from now on in college. There is no one who is going to remind you about due dates. Take initiative to get things done in a timely manner- especially reading, as there will be much more of it in college than you will have experienced before. Know that this is a time of your life to meet people from many different backgrounds however, and do not immerse yourself in studying to the point where you are not enjoying yourself and making new friends. I have sometimes found that I learn the most from conversations with my peers. Regardless, college is a time to develop and experience new things, so do not be afraid to do so!
Hope all is well, and Happy New Year!