In Albion Online, your available skills are dictated by your weapon and armor. This system is much different than what is available in other MMOs, and provides a great sense of freedom.
To select which skills to equip, head to your inventory and click on your equipment. You will notice that you will have one, two, or sometimes even three options for available skills under each tier.
Note that you can easily switch which skills you have selected while out of combat.
By default, skills are bound to Q, W, E, R, and D. You can change this in your settings.