This guide will let you know where to find Hemp and Fiber in New World.
First, you have to head to the middle of the map under Everfall, left of Windsword, as shown in the map below.
To harvest the Hemp, you need to have a sickle, which can be crafted by making a campfire, and you need some specific tools to craft a sickle. Once you have the sickle, you can harvest the Hemp; otherwise, you cannot.
When you get closer to the Hemp, press the E button, and then you will get the Hemp and fiber. Look for the pink flowers on the top of the plant, as shown in the image below.
These plants are the Hemp plants.