Tell us where you are located and we can help you a little better. I've heard good things about Scuba Adventure in Jeff City. I got certified through Scuba Down Under in Sedalia. As for Scuba Down Under, I felt very akward at first, but they quickly took me in (of course I was wanting to spend some money). They quickly became friends of mine and when I walk into the shop now, they know my name and ask me about my recent dive trips.
I just recently (July) got my certification. IMHO, as a newby, let me give you my 2 cents based on my experience. Initially, I felt like a fish out of water (no pun intended). I felt that all the "Certified Divers" looked down on me. But, a good friend of mine who has been diving for several years told me, Scuba Divers are a strange group of people. They take their sport very serious and yes there is a "mocho" thing with many of them. I questioned myself many times about getting into the sport. Not that I didn't want to do it, because I do, but some of the other divers seemed to turn me off. I think I was feeling probably close to what you are feeling. My advise is that if you want to do this don't be discouraged. Jump in ask questions, people will warm up to you. Absolutely, it is important that you find a good instructor. But, you will feel a little uncomfortable and akward initially. I worked with many police officers in KCMO many moons ago, and it's kinda like that. When I was new they really didn't open up to me and really didn't trust me. Once I proved myself and I earned a little trust they became very good friends. I think diving is a lot like this. Don't get me wrong and think all divers are closed minded because I have met in just a few months a lot of good people. Each one is very eager to help and share their stories.
Bottom line, if you want to do it - go for it. Will you feel a little akward - probably. I can't emphasize enough to ask questions. This breaks the ice, shows you're serious and enthused. I don't know a diver yet that won't jump at the chance to explain something to you. They love it and this will open things up and make you feel more comfortable.
Keep us posted on your certification process.
S. Nagel