I have a B.A. in History and Sociology and a M.Ed in Education Policy/Higher Education Administration.
Now as somebody who actually does advisement as part of their job you may want to listen. First of all do not worry about having a declared major when you enter college. Odds are even if you did have one you will change it. I changed my major/minor several times, ultimately ending up with what I graduated with. I had originally declared as Aerospace Engineering when I applied. So do not get hung up over that or lose sleep.
Second while you are an undeclared pick your gen-ed courses strategically. If there are specific subject areas/fields that interest you or you like, take gen-eds offered by those departments. But be forewarned these classes are often large survey courses that are about as exciting as watching paint dry. If something really interests you go ahead and take a 200/300 level course in that major. Even if you do not end up there you will need elective credits later on.
Once you start taking classes GO TALK TO
YOUR PROFESSORS! I cannot stress this enough. Those poor bastards sit in their offices all alone with nobody to talk to. I'd be willing to bet that one or two of your profs in the first 2-years may turn out to be great mentors and you can make a significant connection with them. Which is good because you will need somebody to get letters of rec from. And again they don't have to be in your field of study. You may well find them to be useful sounding boards and they might be able to guide you in the right direction.
Get rid of the notion that you get X degree to get Y job. Unless you are going into a fairly technical field, such as engineering, or are on a pre-professional school track where you need specific coursework to get in, any degree will do. Now with that said remember not all degrees are created equal. If you find yourself in classes with lots of basketball and football players you may want to reconsider
(no offense to you jocks out there). Double majors/degrees are even better in my mind. I personally like seeing a business major (accounting, finance, marketing, MIS) paired up with something like Pysc, Sociology, English, Spanish, Anthro, etc. Double majors like that give you a good balance of practical stuff, plus it will ensure that you will have to read a lot, write a lot (VERY IMPORTANT BTW), and will hopefully mean that you will develop strong critical thinking skills.
Be flexible. No matter how well intentioned your plans are there are going to be many things that get in the way and fuck em up. And as much as I dislike it, there are weed out courses in a lot of majors. Calculus, Physics, Organic Chemistry seem to be the popular ones that flunk a lot of students out. You may need to reevaluate what you want to do and how you are going to get there. It was certainly something that I had to do, several times, as an undergrad, but at this point I am pretty happy with my choices.
Stop drop and roll will not save you in hell. --- seen on a church marque in rural Virginia