I kind of agree with BikeyGuy, get a bit of a groove and a rhythm for the riding, get your body used to the feeling, especially comfortably spinning, its essential for longer riding, I have tended to find you can feel when your body is ready to up the pace, it seems like a natural progression, which I have found in the 3 triathlon disciplines, but cycling the feeling is even stronger.
I guess if you really just want to get quicker look out for a pack and just trying pacing them or if they are very fast, hanging onto the back of a pack for a while that will certainly help your speed and eventually you will be out leading the pack for a stint.
just enjoy it...