No AC or heat

Please help! I bought this car a few weeks ago. When I test drove the car the AC and heat was blowing great. Literally the same day while driving it would go off and come on and go off randomly. The next day it quit altogether. Sometimes I can barely feel air coming out of the vents. I have the glove box off right now but I do not know what to do next to try to find out what the problem is. I have nobody to help me in any way. But I desperately need heat for my two week old baby. Unfortunately I do not have the funds to take it to a mechanic right now due to just having a baby. So if there is anything anyone can tell me please do.
Thanks in advance!