I'm pretty skeptical of how much good a month of martial arts will do you once you're off the mat. Most of the value of martial arts is in conditioning (both physical and mental, e.g. making you more comfortable around people acting aggressively towards you), not technique, and a month of classes isn't nearly enough to build a strong foundation there. Even on the technique side, that much time will give you a few neat tricks but won't allow you to systematize them or to generalize them to unfamiliar situations.

On the other hand, a month is just about enough time to get you past the boring introductory lessons (how to stand, how to fall, how to throw a punch that doesn't completely suck) and into the meat of the art, so that kind of time might be a good sample if you're on the fence about a longer-term commitment.