You have to read about the pen tool and practice now hwrre as this is not difficult to do it is a bit time consuming perhaps about fifteen minutes and some of these guys here can do it in like 3 to 5 minutes.
It is several shapes on top of one another if you do not get the paths correct right away you can adjust the curves using the direct select tool and clicking an anchor and adjusting the handles and you can move the nachor points as well.
You also make shapes for the gradients by copyong the underlying shapes and placig them on top of the under lying shapes using the layers panel for the gradient overlays use a blending mode of Multiply which you assign with the transparency panel read about the transparenc panel as well in the help files.
Here is the anatomy of the art. Also sty calm you can fix if after you draw if it is a little messy. Yu should probably trace the art though I never trace someone else's art.
Here are the individual paths (shapes)