From the start of the game, tutorial boxes will appear in the top left giving you tasks. The first few are very simple as they are just teaching you the game mechanics, so you need to look around, jump. change camera etc. This is followed by finding a chest to open (there is a small cave part with some stone blocks. Destroy these to find a chest behind).
Keep following these tasks, and you should get this. My last one came when I went through the portal and then killed 2 enemies to level up. Assigning my points and a skill from leveling was my last objective.
Note it is possible to turn off the tutorial and miss this. I haven't tried this to see if you can obtain it later on your character, but if it doesn't work later, you can always create a new character.