Oh hell,,,, that's your tattle tell hole it's pissin out of. When your water pump deal is shot it pees through there to let you know instead of filling your bottom end full of water.

Super stoked you got her fired up though!!!! I agree, after you run it some it'll get easier and easier to start. You'll learn the sweet spots and all her quirks and will have it down to almost a science.
I didn't have my 500 for long and only rode it once but it was such a pain to start at first simply because I didn't know how to. Then I figured it out and every time it would fire right up. And mine was sitting on an engine that had quite a few races on it.

Still, REAL glad you got her running!! I hope she does you well! And like I said, scope out that water pump seal