Finding a major

First things first: you are not forced to keep the major you choose as a freshman. In fact, entering as "Undecided" or "Exploratory" is completely acceptable, and very common. When you do decide on your major, that does not necessarily tie you into working a specific job for the rest of your life.

There are three important steps to begin your search for a major:

Ask yourself, "What do I enjoy doing often?"
Find ways to do that often
Ask others who do that thing for a living how they got there

If you don't have a thing, do more things: volunteer, make a club, join a Circle, take an elective you hadn't considered, join a college tour, attend our college events

Resources

There are lots of websites out there that will offer to find the perfect major for you. A few are listed below, but do recognize that most are businesses: they will likely give you good information, but are making money somehow. (Ads, usually, sometimes by selling your information [1]). Here are a few that do not (to my knowledge; contact me if you see I am wrong):

Kuder Interest Assessments is used by the University of Tulsa to help students find their passions. [Note when signing up you'll need to search for "Tulsa Schl"...]
Most universities will have a "find your major" tool that will guide you toward majors offered by their institution. Here is OSU's tool and OU's tool. Find a similar tool by searching within most colleges' websites
Remember the long set of questions you fill out before taking the ACT? That is an assessment, and your test results will give you recommendations based on your scores and responses. There is a section of ACT's website devoted to this information

If you know what you would like to study, but are interested in the job opportunities it affords, What Can I Do With This Major? is a great tool to flip through.

Some universities allow you to create your own major. Here's a familiar face describing her time at the University of Tulsa: