If you have the ability to shower near/at work, it can make life so much easier, especially in the Summer.
As others have mentioned, there is no secret handshake or hidden magic to commuting - just some common sense and a desire to do it. Welcome!
I tend to wear a variety of clothing - anything from running tops/shorts to old mountain bike shorts and mountaineering layers - all of which I just have anyway. I dispensed with my old "roadie" lycra gear because I no longer have the desire to wear it, though some prefer it. It is really wide open.
If I had limited funds, I'd prioritize safety lighting first, and a set of slick tires which will offer better ride quality and more efficiency for the distance you are riding.
Oh, and don't do anything to provoke Chipcom - once you've seen him in a dress, you will never be the same.