As for grades/application requirements, I had a 3.35 undergrad in psychology and a post-bac 3.9. I took the MCAT instead of the GRE, with a 504, which is a pretty average score for reference. I also had a lot of hours volunteering in hospitals, shadowing different types of physicians, and little actual AA shadowing, but had a lot of knowledge about what the program and profession entailed.
It seems that my class has a wide range of backgrounds from finance, mechanics, EMT, etc. And another large range of shadowing and volunteering experiences.
Please let me know any other questions you may have, but if you have decently above average grades/scores and have a good grasp on what the AA profession is and why you want to be a part of it, you should have no problem getting in. Good luck!