Skyshard is behind a house, at the very edge of southwestern part of Stonefalls. In this area you can complete a couple of quests that rewards with fair amount of experience and loot level 13. This is a great area for leveling your skills, since you will come across a lot of creatures. Also, running towards the skyshard location without fighting any creature might be a challenge.
Sand Kingdom Moons - Super Mario Odyssey Power Moons