The Dawn Tree is the yellow tree on the bottom left-hand island, to expand onto it you need to first clear the left-hand side of your starter island. When you've cleared enough from there you will be able to expand. Hope this helps :)
Oh plz disregard, I found the answer to my question: Mystic maps can be requested from neighbors each day. Neighbors can accept your request to give you a mystic map at no personal cost. However, you are limited to one mystic map request per neighbor daily.
First question: Go click on an expansion plot, attempt to expand by clicking the Expand button, and from there you should be able to see how many maps you have. If you do not have enough, you can then click a button to request maps, which will take you to your neighbors list. (Be VERY careful not to click the "buy" option, because maps cost an ungodly amount of gold and if you have enough gold to buy them all at once, the game WILL do so).
Second question: Answering requests from neighbors does not cost you anything :)
Umm, still unclear on a coupla things though: I can’t find a button to request a map. Got one neighbor, (by default? Cannot remember him asking), but he seems to have no such button.
And if you get a map request, do you have to pay to give one away?
If so, gold or coins?
No. It is free, and you don't have to give a map/gold.