Rather than hiring a captain, it might be more useful to engage a good instructor for a few days. .
I think that is a really smart suggestion if you are concerned about your abilities to maneuver the boat right now.
This whole boating thing is not rocket science. I suspect that the majority of participants on this forum did not hire instructors or captains, they simply "got into boating." Many of us started with smaller boats and worked up. For me the progression was a 12-foot Sears aluminum skiff with a 6hp outboard, then a 17' Arima fishing boat with a 90hp outboard and 6hp trolling motor, and then the 36' Grand Banks.
The only formal instruction I and my wife had was when we chartered a GB36 prior to buying one. The charter company's checkout skipper spent a couple of hours with us reviewing docking procedures and he gave us some tips and techniques on docking and undocking and picking up a mooring buoy that were invaluable and that we still use today. Other than that, we just went boating.
Perhaps as a result of a lot of years flying planes (and my wife owned a couple of planes, too, before we got married) both of us are very good at recognizing our limitations and taking baby steps to advance them instead of jumping in over our heads.
You're not new to boating so this trip you're planning should be no big deal. Sure, you haven't been down the route before (I assume) but a boat's a boat so the only real new stuff to you will be what you encounter along the way.
Others have mentioned a number of resources to help you get familiar with what you'll encounter. Everything from Google Earth to the charts to Active Captain to guidebooks (I assume there are good guidebooks for your route) will help.
My wife and I were lucky in that for over ten years prior to our buying the GB we had flown many times at low altitude (usually less than 1000') the entire inside waters region between Seattle and Juneau and so at least knew what everything looked like between here and there, the relationships between all the islands and the mainland, and the water conditions.
That didn't help when docking at some harbor for the first time in an adverse wind but it did help to know exactly where the harbor was in relation to everything else and what we'd be likely to encounter getting in and out of it.
So I'd say get a bit of instruction on your boat if you really think you need it and then head out, taking it easy and using all the information you have on hand. The experience you have every day will become part of the next day's data base and before long you will be wondering what it was you were worried about.
We'd never driven a twin-engine boat before we got our GB (the GB we chartered was a single). So we were both pretty concerned about maneuvering and what to do entering and leaving a slip and so on. To the point where I asked a good friend who had a twin engine deFever if he'd give us some lessons in Lake Washington. He said sure but we were never able to put this together so in the end we took his advice and just went out and did it, taking it easy and using as much common sense and logic as we could muster
And it proved to be no big deal at all. In fact manipulating twin engines and drives proved to be so intuitive that we soon wondered why we'd been so concerned about it or had even thought about lessons.
I will not be surprised if your experience is the same.
Just don't get cocky because that's when Bad Things will happen.