First of all the skills that got you the job, got you the job, so they're pretty comfortable with who and what you are, so take confidence from that and do what you're there to do to the best of your abilities.
In addition, you might want to consider - being proactive in identifying problems, and inefficiencies plus possible solutions; once bedded in start asking for more challenging work; take any opportunity to develop your skills and breadth of experience; if possible identify a mentor higher in the company who is a long term employee - learn from him or her what works/doesn't work.
Finally support the people around you, including your boss - the above plus being seen as a team player will stand you in good stead.