Find the small tree in the game, as shown in the picture.
When you find it, use the stone knife on the small tree and press the left mouse button to chop the tree.
After cutting it down, you will get a wooden stick and a long wooden stick. If you are missing wooden sticks, right-click on the long wooden stick.
Click Harvest when the option appears, as shown in the picture.
If the harvest is successful, the system will put the stick into the backpack.