PICKING YOUR DEGREE AND THE THREE REQUISITES OF THE UNDERGRADUATE
First off, you need to pick a degree you know you can excel in.
You can major in art and apply to medical school if you want, as long as you have the prerequisites to apply. You do this because your GPA is of VITAL IMPORTANCE depending on whether or not you want to go further academically with that degree. Whatever you do, you have to keep in mind the next few things; 1) GPA 2) Program Examinations 3) Recommendation.
For your GPA, if you leave with a 3.0 on a 4.0 scale, you are in the 70th percentile of people applying to graduate and doctoral programs. This means that you have half a chance of getting into a school of your qualification on the first try, and the odds increase the more you apply. Also, a track record is important, you want to show that your grades show a steady increase as you go through school.
For program examination, keep in mind that at the end of your run, you are expected if you wish to enter a professional school to take an entrance exam, like the LSAT (Law) or the MCAT (medicine).
RECOMMENDATIONSGETTING A PHILOSOPHY DEGREE
What can I say about a doing a degree in philosophy? Philosophy is for the most part like getting a history degree. It is really never about your own opinions, but the intake of what others have said, which is I guess obvious. You excel in a philosophy degree by getting at least a B average and establishing a relationship with your instructors.
LEVELS OF CLASSES
Depending on your initiative to retain that knowledge, you can take (within the American school system) classes leveling in difficulty. Most colleges do regular classes and honors classes. This is pretty standard for most schools. My school does regular classes (1000-3000 level courses like continental philosophy, religion, etc.), honors classes (H 1000+2000 level courses like existentialism), and Masters level courses (4000+ level courses like metaphysics) As an undergraduate, you can take masters level courses and actually apply them to your masters degree if you wish while also counting towards your undergraduate degree, making a 2 year masters degree track into a one year stint. Another interesting fact is that if you wish to apply for a Ph.D., you need not necessarily go through a master's degree first, you can directly apply if you are notable.
I should point out that Philosophy is within the liberal arts college at most universities, and you will have as much help from advisors (who try to pick these classes out for you) as you would from some stranger on the street.
TYPES OF CLASSES
In the Philosophy degree, you have three types of classes; core, major, and elective.
The core classes are those which the university wants you to take. These are basic, sometimes nonsense classes. But this is important to note, in that these initial first year courses establish your GPA. Take easy courses that you know you can do well in. These are introductory classes to all aspects and curricula. However, the required courses sometimes intersect with elective courses, as you have to take a number of sciences classes and the like.
The major classes are classes you are required to take in order to graduate in your major. In these classes, you have a variety of courses in philosophy ranging in difficulty, culminating in a senior seminar.
The elective classes are those which can be anything you want, but you can only do so many that count towards your degree.
My philosophy degree is composed of 127 credit hours. Within those 127 credit hours, I have elective, core, and major courses that need to be fulfilled in order qualify for graduation. I have 163 credit hours, as I have two minors that go beyond the required credits. The credits that go beyond the 127 credits are worthless unless you fulfill the minor requirements, which is basically a mini degree. Minors are extremely dangerous as you can screw up your GPA if you are not careful.
I hope any of that helped. There is a lot more to say, but I may be saying too much. If you would like to talk about hashing out a plan for your college career or making a decisive cut for a profession, I'd be happy to talk about it. God knows I've had an earful of it, but it in the end paid off.