Everyone travels differently and does different activities. I think the best you can do is set a budget for you alone and have some extra stashed for an emergency. If you go under budget think how good it will make you feel. If you need to go over, you'll have the extra money. You just can't plan exactly.
This is your first long trip. You'll learn lots along the way. None of us knew at first how much traveling and doing things cost. We were all beginners at one time. Your second trip will be a breeze.
I've given my suggestions in your original post. Just GO!!!