What basic courses do I need to take to get a good grasp of account payable?

I have worked as a legal istant for a long time but jobs in my area are very few and far between. When a position opens all 300 are applying for that one job, ugh! I want to give myself a better chance of getting employed, anywhere! What cles can I take at a community college, I will be going to Mira Costa College in Oceanside, that will help me understand and be able to perform an accounts payable job? I have been looking for job since October and I need to try to get as many skills as I can. THANKS EVERYONE!