1. After you talk to Dennis outside of Amanaki, the pause menu will come up, and CRAFTING will be blinking. Click on that.
2. On the right, you'll see an entry for Medical. Double click that, and you'll see a new entry for Medicine. You can click it, then click CRAFT on the bottom, or you can double click Medicine. Either will create one Medicine syringe. You'll need to make two in order to progress.
3. Then, on the top right, the bag icon will be blinking and have a yellow circle with an exclamation point. Click that to bring up the Equipment Crafting menu. Click Loot Rucksacks. It will be replaced by the Simple Rucksack. Again, you can double click it, or single-click it and then click CRAFT on the bottom.
4. Dennis will now start talking about the Tatau. The game will automatically bring up the Skills menu. When Dennis says, "Now, I will teach you the takedown," you'll want to click the shark in the top right. There will be a skull with a knife in it that's a bluish-gray color. Double clicking the icon will bring up a pop up, asking if you'd like to Learn it. Click OK. It will now bring up a repeating video, showing you how to do a take down. You can then click cancel and move on to the next skill.
5. Now, click the Spider in the top right. In the center, there will be an icon of man sliding, again in a bluish-gray color. Again, double click this icon to learn it.
This ends the tutorial, and Dennis will talk to you face-to-face and allow you to continue with the gameplay.