You can help another creature by completing a task. When you perform the Help action, the creature you help gains an advantage in the next ability test you perform to perform the task you are helping with, provided you do the test before the start of your next turn.
Alternatively, can you help a friendly creature when attacking a creature 5 feet from you. You feign yourself, distract the target or, in some other way, team ways to make your ally's attack more effective. If your ally attacks the target before your next turn, the first attack roll is made with advantage.
The Help action works on your (designated) ally, not on the target.