That is one heck of a first cruise! You really jumped in with both feet. You will have an absolutely wonderful time. I've done the same cruise in reverse twice (but only as far as L.A.) and on Princess, not Holland America. But I've been on HAL and I can't say enough good things about them.
If there is one thing I could tell a first time cruiser, it would be to relax and not worry about a thing; everything will be taken care of for you. There will be a crew of close to a thousand people who want nothing more than for you to have a seamless, effortless, and perfect vacation. All the worry beforehand about, "should I take this; should I do that; what about this or that; what if . . .? is all wasted energy. All you have to do is show up.