Most schools will require that you have somewhere in the neighborhood of 70 credit hours worth of prerequisites before you can apply. These courses will be specifically outlined on most university websites. The best way to really get a feel for what you need to do is to pick a few colleges that you'd like to go to, and then research those programs. You'll be getting into general chemistry, organic chemistry (labs for both), physics, general biology, cell bio, genetics, etc, as well as a few oddballs like economics. Through this you'll most likely need to get above a 3.6 GPA or so (the stats of the average applicant are usually also on their websites, the avg at UK is a 3.8 I believe).
After you've got those courses under your belt, you'll need to take the PCAT, which is the Pharmacy College Admission Test. It's going to cover biology, chemistry, physics, basic math (trig, some calc, etc) and verbal ability. Average score here at UK, as an example, is above the 90th percentile.
Your GPA and PCAT scores will be the main things that get your foot in the door for an interview. All of it is very doable if you can get a study discipline going. Being a non-traditional student, in that you have a military background, is likely to be a plus, certainly. While in school, if you have the opportunity to do anything that sets you apart from other applicants, like research experience and DEFINITELY working in a pharmacy, it will be a big help.