To better understand Nietzsche, it might help to read some Kant, and maybe some Schopenhauer. This will help contextualize where Nietzsche was coming from and where he was going. He looked at them as the foundation of moral/Christian philosophy of which he criticized.
This would be ambitious reading, of course, but it certainly will broaden your views on morality today. And it's not like I'm suggesting reading all of it in the original German.
Thinking about these things only reminds me of all the things I want to read.
How frustrating.