Success in college begins with thinking ahead and discovering what you intend to accomplish. Once you figure that out, decide what sort of college is best for you, and then be concerned more with what you learn than what grade you get.
Probably the best foundation for success in college is to do well in high school. People with mediocre achievements in high school do get admitted to college, but they often have to take remedial courses. Students who need more than one remedial course hardly ever even finish at a two-year college, let alone earn a bachelors.
(If you goofed off through high school and did poorly, that does not mean all is lost. It should not be hard to find stories of people who started college from a place as bad as where you are or worse, turned their life around, and earned not only a degree but a new outlook on life. Don't give up. Look for role models.)
It also helps to take a personal inventory while still in high school. You need to know your skills and weaknesses, what kinds of subjects you enjoy and what kinds you don't, and, generally speaking, what gets you excited. You can't plan your whole career path in high school, but you can identify a general idea of what you want and choose accordingly.
Too many students drift into college because they have no idea what they want, and it seems to be the thing to do. The sooner you take time to find out what you want in life, the sooner you can think of what it takes to get there. Once you have decided that you need to go to college, you need to choose a college and a major.
Traditionally, students have had to make choices based on whether they want to go to a state school or private school, large school or small school, city or large town school or rural or small town school, college or university.
As to the latter pair, a college usually offers nothing higher than the bachelors degree. Community college offer both academic, vocational, and enrichment (non-degree) classes; the academic classes comprise only the first two years of a four-year college and culminate in an associate's degree. Students must then transfer elsewhere to complete the bachelors.
Universities usually offer at least masters degrees in some of their departments. At the very least, they will have more than one "college," such as College of Liberal Arts, College of Business, College of Education, etc.
In recent years, a new option has arisen. People can now get their entire degree online, either from a traditional college or university or from a number of new institutions that offer only online degrees.
Online degrees seem best suited for people who did not attend college at the usual age and decided later in life to get a degree. The advantages for those people is that they don't have to pack up and move; they don't have to quit whatever job or other obligations they may have; and they can look at course lectures on their own schedule, not limited to whenever they occur live.
Some colleges offer a different model of distance education. Students can check out lessons on DVD or other recorded medium and consult with instructors on campus, usually during specified office hours.
Distance education of either kind has one glaring problem: without a set schedule, many people lack the self discipline to finish their courses. In fact, a high percentage of people who sign up for any kind of class with a flexible schedule will not even begin the work.
That fact underscores the importance of self-discipline to success in anything. There is no need to go into detail explaining how to choose a major. Follow your interests and your heart. Don't let anyone else make up your mind for you.
Also, don't obsess over your grades. Graduate schools will care about your grade point average. Employers will probably not. If you don't quite grasp the material in some class well enough to get an A, but learn it later through some other class, you can still demonstrate that you know it. That's what counts.
Learn the material in each class. Build on what you have learned in whatever you take the next term. Diligently work through the curriculum until you have completed all requirements for your degree.
College is not all about academics. Unless you are that older person with a spouse, a house, and a job, you should also get involved in extracurricular activities. For one thing, they will help you stand out when you're out of college looking for work. But the advice in this article will get you through the academics to the degree.