Suggestions For My Magic Story-i Need Help?

ok so im writing a book about a girl who finds herself in another dimeniton that is full of imortal magicians that 100 years ago came across a magic box that gave them imortality and power through there emotions.
Im stuck on what this magical world should be like.
i dont want it to be old fashioned like the chronical of Narnia but it cant have schools and roads like normal life.
this place is based in a forest.
if you have any suggestions please tell me
also suggestions of how she gets to the magic place????