window shopping is a great way to learn. The salesmen (even the sharks) will tell you lots of stuff about mics, and PAs etc. Take it all with a grain of salt, review their thoughts in your head as the days go by, and take what you can from it. Some info will be good, other is just sales talk. As you compare 'words of wisdom' from salesman to salesman, you'll begin to sort out what makes sense.

good luck ...