Set your destination to Kiyak’s Villa or Tasaila’s Villa. It can be found on your map even if you have not discovered it. It is a blue hotel-like icons around the bottom right of your map.
Once you have reached it, Valencia is just located in the East of it. No compass required. You should automatically “discover” Valencia on the way.
The path is relatively trouble free with the exception of the pathway from Shaktu and Bambu Valley as there are Gahaz Bandits potentially blocking the path. You should manually sprint your horse and navigate when you reach Gahaz Bandits
Take note, if you auto path, due to a bug in the game, your horse may stop for no reason at Yalt Canyon (Gahaz Bandits mobs!!) and at Ancado Coast (no mobs). Thus you should monitor the journey especially for the bug stop at Gahaz as they can kill you + destroy your trade goods.
Use this online map to help guide you if you get lost.
Arehaza Town
Head east from “Shandi’s Villa” manually (don’t auto navigate). There are a few small areas without navigation.
You will eventually reach Palm Forest and finally Arehaza Town. Valencia’s second main quest also has a map pointer there towards the end of the quest line.