Minoxidil can cause some shedding initially, but that's just making room for the new and stronger hairs. I wouldn't sweat it if I were you because it probably won't last very long. If it's too bothersome, you really should consider a concealer like Toppik or Nanogen. I recently started using Toppik and it really does work as long as you don't get carried away and are careful when applying it to the hairline. I had a big hole in my crown and very thin hair from there to my forehead, but the Toppik conceals it completely with just a few shakes. I couldn't believe the difference. Some people here say nanogen is a little better, so you might ask around before deciding which one to get. No bigger than your bald spot is, one of those products would almost certainly make you a happy guy.
And yeah, the equate brand of minoxidil sold at walmart is about the best deal you'll find, at least that I know of.
Don't just take my word for it, though. I'm a newb here just like you. There are plenty of people here with helpful advice.