You should not have any problems with Class C. There are a few more freq changes. I'd make sure I'm familiar with the airport diagram, know where I'm parking, and how to get there from each runway. You could request the runway that will give you the easiest taxi to/from the FBO. Get the ATIS before initial contact if you can.
Our class C (KCAE) is usually quiet, but there can be busy times. YMMV
Let us know how it goes.
Here's a link to KCOS. HS=Hot spots, places where the probability of screwing up are raised.
<insert legal disclaimer about chart here>
http://155.178.201.160/d-tpp/1311/00087AD.PDF