"I do not have time this evening."
Translation:Ik heb vanavond geen tijd.
Now I'm no native Dutch speaker, but from what I understand, when a direct object is definite, it will come before the time, manner, and/or place in the sentence; inversely, if it is indefinite (like in our sentence here), it will come after the time, manner, and/or place.
Use "geen" when you are negating the object. For example, "Ik heb geen water" means "I have no water." Compare that to "Ik heb niet het water," which means "I don't have the water. " In the first case, it is the water that is negated, but in the second, it is the having that is negated.