If you've never sewn anything in your life and want to do this as your first project.... well, that's sort of like entering the Indy 500 race when you've never driven a car. Sure there is a chance you will take to it naturally and win, but the chances of crashing and burning are much, much higher.
On a scale that goes like so:
I'd call this costume advanced
Does that mean you shouldn't do it? of course not!
So long as you understand that you will need to do a lot of test pieces and practice runs and this project will take months, not days, to complete.
Personally, I'd work from the top down. Break it into it's component parts (bodice looks to be separate from the sleeves, so that is one piece, etc.) Find patterns as close as you can get to that shape and work from there.