Most of us have had a job at some point in our lives. We know that when you are the new kid on the block if you are not an extrovert, it may be a bit hard to get a word in...among other things.
As a sometimes member of this group, we should step out of our comfort zone a bit. We don't want to be known as that weird girl/boy who does not interact! I'm sure thats what people say. So, leave that guard you have up at the door. When co-workers invite you to go somewhere to lunch you don't have to go all the time just go a couple of times and join the conversation!
We know you have an amazing personalities but sometimes it is best to tone it down a bit when you are the new kid on the block. No one wants to be known as the loud annoying person they try to avoid at all costs. Get a feel for the environment and slowly emerse yourself then, it will feel natural for you to show off that larger than life personality of yours.
For all the In-Between-ers:
Well, just play it by ear :)