What do you think about morality?
It can be useful or meaningless, helpful or dangerous, depending on the circumstances.
Does the concept of right and wrong exist?
Of course the concepts exist, we work with them every day. Is there
actually right and wrong? I don't know, but I think that's a less interesting question than, say, how we apply it or how we come to think of something as right/wrong, etc.
And if so, how do you define it?
The most general ethical principle I can think of is where you don't do to others what they don't want done to them or their property. Non-initiation of force is also a big one.
If right and wrong exists, what makes something right or wrong?
How it affects the recipient/subject/victim of an action, and what they think of it.
Do humans have an inherent moral nature?
Yes, but it relies on a few fundamentals that can easily be ignored for one's own selfish reasons. Mostly, it relies on you seeing other people as their own moral agents and not philosophical zombies. The selfish - in some ways rightly so - have no reason to value someone else over themselves, and so act towards their own interests more than those of others.
And if so, do you think humans are naturally good or evil?
Humans are naturally wonderful and deeply flawed. Anything else seems like too much of a generalisation or simplification.
Is morality natural? If morality isn't natural but still exists, then why does it exist?
Morality isn't natural as a thing unto itself, but it is emergent from natural and non-conceptual things. Animals working together in a pack need some very basic morals to function better together so as to survive, for instance.
I'll add more thoughts when more responses come along. I could offer a lot more, but I think starting a thread's replies with a wall of text isn't the best way to begin on such a topic many of us can contribute to.