Good for you! I, too, am going back to college (for the 2nd time) after 1.5 years of absence. I’m studying music/vocal performance (but my real desire is to compose).
–Choose your friends carefully. Recognize that you are older and more mature than most of the other students. Picking friends who are too young or immature could get you all caught up in drama and leave you feeling drained of energy. I know this sounds silly, but it happened to me.
–Make sure you have, or will have, enough money before you even start. Money problems that come up in the middle of a semester could cause you to drop all your classes, making the whole thing a waste of time. Not to mention, you don’t need to be worrying about money when you’ve got tests to take and classes to pass.
–Explore internships in your field while you are still in college. You’ll be much more likely to get a job if you have actual work experience under your belt, and internships are one of the best ways to get your foot in the door.
–Meet people and make as many connections as possible! This is the best chance you’ll get to meet a lot of others in your field. The relationships you create now will help you in ways you cannot yet see.
–Do not get overwhelmed! You’ve been away from college, and now you’re diving head-first into a complete life change. Do whatever you need to do to keep yourself sane, and do not be afraid to take advantage of the college’s counseling services. They provide it for a reason!
–Eat a well-balanced diet! Malnutrition will make you irritable and make it much harder to keep your grades up.
–Last but not least, do not be discouraged if you see that many students lead very un-Christian lifestyles. Remember that you are not responsible for anyone’s actions but your own, and you need not get too wound up over others. Pray for them and move on. Don’t try to “convert” anyone; they will probably not be open to such things at this point in their lives. Let the Holy Spirit speak through your own example of charity to them.
I hope this addresses at least some of your concerns. These are just some of the things I have learned over the course of my own quest for graduation.