It is possible to get confused if you only read the in-game objectives. Read the quest description instead Lost Ark Gold; it mentions something in the following manner: "These Hoarfrost Robbers don't know when to give up. They continue to show up at the Frozen Harbor, taking from merchants and the residents."
This means that the first thing you must do is sail to your destination, the Frozen Sea Harbor in Shushire or teleport to it using a Bifrost. Don't forget to set the Bifrost's location to Shushire for the next time using the icon below the minimap, if you don't already.
Once you're there, all you need be doing is defeat those Hoarfrost Robbers who are terrorizing citizens. Find and eliminate 50 Robbers who have been swarming in the vicinity. If you're not able to locate them, head to the northwestern part of the harbor, usually there's a plethora of them there. That's it; you'll be able to complete the "Ride Like the Wind" Quest at that point.
The various layers guarantee that players always need to work on something and, in addition, a "correct" order to do these things in Lost Ark Gold buy. This is the kind of endless potential for skill that makes Lost Ark's classes so much fun to take part in, no matter how much time you've already spent trying to master them.