Your level has nothing to do with your entry into Dragonspyre.
Just as you had to complete your required assignments in Wizard City before you moved on to Krokotopia, and had to complete your required assignments in Krokotopia to move on to Marleybone, and had to complete your required assignments in Marleybone to move on to MooShu, (see the trend?) you will need to complete your required assignments in MooShu before you can continue the story progression into Dragonspyre.
Complete the quests you have in your quest journal for MooShu and others that open up as a result. Only once you have completed your required assignments in MooShu will you unlock the door to Dragonspyre.
i was told by my friend who is a higher lvl than me and he said that when you get your last spell the myth teacher calls you to fight him and he gives you the key to dragonspyre.
you have to fight the Jade Oni in MooShu first (you probably want to bring some friends with you). after that you go to headmaster ambrose. then he will send you to the myth professer. you will then have to go to the myth tower and defeat him. once you defeat him, you have access to dragonspyre.
