Where to study quantum mechanics?

By BBA do you mean Bachelor of Business Administration? That's a, if you'll forgive the pun, quantum leap away from physics. That would be like going to college to study physics, then switching to philosophy and become a lawyer (which is what I did).

Anyway, you can totally study quantum mechanics as an undergrad. I took Quantum I and Quantum II at Cornell and I was a philosophy major. (I worked out a deal to take Quantum II pass fail and write a paper on the philisophical implications of some of the areas were were studying as part of my grade, which turned out to argue that an analysis of liquid helium suggests a type of mereological perspectivism that I'm sure my professor didn't understand. I couldn't have done the math required to pass that class without this deal and I really wanted to learn the concepts.)

At any major university with a physics program, if you study physics as an undergrad, you'll not only be able to learn some quantum mechanics, but you'll be required to, along with special relativity and, of course, conventional mechanics and electro-magnetism. If, after completing your BS, you want to go on to grad school, you'll be able to study quantum physics in much more depth. At that level, you'll need a good understanding of relativity as well since areas like quantum chromo-dynamics and the workings of particle accelerators depend heavily on it.

Grad school programs in physics are very difficult and very competitive, so don't even try unless you've done well as an undergrad (I've known a few people who graduated Cornell and still couldn't hack it as a physicist in grad school, they were only a little better than me at physics, you've got to be a lot better than me at physics to make it). But if the area interests you, pursue it. Start with an undergrad physics degree, then specialize in an area of physics in grad school.

If you just want to take a course out of interest without the expense and time of going back to school (also without the degree, so you couldn't work in the field), you can do that at community college. I'm sure they'll be happy to have you. Talk to the professors there about what courses you'll need to take in order to learn what interests you.

Let me give you a bit of perspective, since I am a quantum physicist. First off, it is not taught to people in the general population because it requires complicated math, well beyond what the average person will take in college. And, though it is applicable to a very broad range of topics, the general population will never need to know quantum. I have never learned the different symptoms of cognitive disorders because I am not a psychiatrist and that has no impact on my everyday life. Similarly, a psychiatrist doesn't need to know the intricacies of the quantum measurement problem. Quantum is a specialized field and takes a lot of effort to explain and many years of hard work to understand. That being said, now let me turn to your knowledge of quantum. There seem to be some very big errors in your understanding of quantum, which makes it a bit odd that you are proposing everyone learn quantum. First of all, relativity is not related to quantum. In fact, relativity and quantum contradict and physicists have yet to figure out how to reconcile them. Second, anytime someone brings up quantum and spirituality, everyone who actually knows quantum immediately assumes they are talking to a quack. And there is good reason for this: quantum says nothing about spirituality. There is no more connection between quantum and spirituality than there is between Newtonian physics and spirituality. I have no idea what in quantum is helping you with your spirituality, but my guess is whatever it is, it is not part of quantum physics. The problems is that a bunch of quacks have hijacked quantum mechanics. They take statements said by actual scientists, then twist them around to say something else and then apply them to spirituality. But what they say is no longer related to the actual science. All of this 'quantum immortality', 'quantum jumping', 'conscious observer', and so forth is all a bunch of hooey. And I get the feeling that there is more misinformation and misconception out there in the general public on topics like the measurement problem and entanglement than there is actual information and understanding. The fact that you are equating quantum and spirituality strongly suggests to me that you actually know much less about quantum than you might think you do.