I think my main worry for the first time is accidentally misreading a chart and running aground, or getting into heavy weather. I will be the first to admit that at this stage of the game I consider myself a fair weather sailor.
It's pretty easy to avoid running aground in the BVI. If you've been through the ASA classes then you've learned more than enough about how to read a chart. You just need to use a little care, pay attention, and remember that the chartplotter is only an aid to navigation, it is not a substitute using your eyes and your brain.
As for weather, it's not likely to be bad, but one of the things about the BVI is that everything is pretty close by. See bad weather coming? Head for a secure anchorage and sit tight while it blows over. No big deal.
I would also say that I think most of those who are new to picking up a mooring probably over-think it. I know we did. In reality, it's pretty easy. The biggest trick is to get the boat to stop where the person at the bow can grab the pendant with the boathook. The first couple of times my wife either didn't give it enough reverse (so the boat went past), or gave it too much (so that we started backing away). Again, no big deal; we just went around and tried again. After a couple of times she had it down perfect.
From then on picking up a mooring was easy. Pull up, stop, pick up the pendant, thread a dock-line through it, cleat off, done. Piece of cake.
I'm sure everything is going to go fine for you and by the end of the first day you will realize that all of your concerns were for naught.