as everyone else stated, don't rush it. I borrowed gear for several months before i purchased. Scubatoys dot com . Great prices, fast shipping, knowledegable employees, lenient return policy...
If you are gonna buy something, buy a mask. They seem to all fit just a little different and trying to keep a different mask dry each time you dive will not be fun.
Fins are the second thing i would buy. So many choices and everyone has their favorite. Get the spring straps if you can afford it, much easier to put on/off. Sounds silly, but trying to get your fins off on the side of a boat with waves grating you against the ladder is not fun.