Some pharmacy schools will require at least 2 years of college (pre-requisite) work before you apply into the PharmD program, and some will require a Bachelor's degree (4 years of college) prior to starting the PharmD program. When you decide to apply, look up the requirements for the schools you intend to apply to, and this way you know what courses you need to complete in College before applying. Doing this research first saves you time in College so that you are not taking classes that you do not need.
The PharmD program itself runs 3 to 4 years depending on the school that you get into. Some people will do residency afterwards for a year or two to specialize. So basically, it takes at the very least 6 years from start to finish. The years could add on depending on the reasons listed above.
Let me know if you have any more questions.
Jennifer C. Iwegbue, PharmD