Social stealth has been one of the trademark features of the Assassin’s Creed franchise. However, with the new direction the franchise took, it was missing from the past few iterations. In Assassin’s Creed Valhalla social stealth does make a come back, and so does the cloak, however, you don’t get it straightaway.
To get the cloak in Assassin’s Creed Valhalla you need to wait until you unlock the Birthrights mission. That is, when Basim, one of the Hidden Ones, gives you the cloak. This mission also serves as a miniature tutorial for using the cloak in the game, however, it doesn’t explain much how to use it properly.
The cloak allows you to move around without getting detected by enemies. However, it isn’t that straightforward. If you get too close to enemies, they will spot you. Walking too quickly or running raises the detection bar as well. Moreover, if you draw out weapons, that will alert the guards as well.
You can use the cloak by bringing up the quick action menu (D-pad down) and then selecting the cloak. The cloak can be used to avoid unnecessary attention by sitting on benches or standing in a group of people to blend in. Additionally, you can promise people that you will get them a drink, and they will follow you. There are numerous ways to blend in the game, so it all boils down to the situation you are in and your creativity to get past enemies without being detected.