Can I join the Army with prior misdemeanor charges?

Depends on what the charges are for. The best thing to do is just sit down with a recruiter, get some information and explain the situation.

"The military requires applicants to be of good moral standing. This means a recruit must not have committed any serious crimes. ... Any applicant for enlistment in the United States Army who has received two, three, or four civil convictions or other adverse dispositions for a misdemeanor offense.requires a waiver."
-Quick Google search of "army enlistment regulations misdemeanor"

Most likely. I had an assault charge and a couple of rather expensive traffic stops and a waiver wasn’t hard to get for it, just took time. Assuming you’ve been on good behavior for a time you should be fine as long as it isn’t domestic violence or something.
Recruiter will tell you up front what your chances are once you explain the situation accurately and honestly. That last part is important because they’ll bring up your records for your packet early on. I hit a bump after a miscommunication occurred and my recruiter was unaware of how my traffic stops were laid out, but all that did was delay me a couple weeks.