What is the mounts?
Mounts are for customize your character, do some quests and also walk more faster. To toggle between mounted and unmounted you may use the hotkey Ctrl+R. You will automatically dismount if you enter a Protection Zone, but you will automatically remount when you leave the protection zone, if you were mounted before entering it.
Free Account players can tame creatures and earn achievements for them, but they will only be able to ride any of the “permanent” mounts unless they activate some Premium Time. However, mounts purchased through the Payment System can be used in-game whenever you want, no matter if you are a free account or a Premium Account.