You've got the maps already installed into the game, but you can also download a map and the portal will be in Cape.
Tutorial here. (http://www.feral-heart.com/index.php?option=com_jfusion&Itemid=2&jfile=index.php&topic=8166.0)
And a video to make things easier.
http://www.youtube.com/watch?v=1ULvvPVJIk0&feature=related (http://www.youtube.com/watch?v=1ULvvPVJIk0&feature=related)
How to install items.
http://www.youtube.com/watch?v=9gO5YwwGxxc (http://www.youtube.com/watch?v=9gO5YwwGxxc)
The most used ones.
Ouka's stuff. (http://www.feral-heart.com/index.php?option=com_jfusion&Itemid=2&jfile=index.php&topic=22971.0)
Ringo and Delay's (http://www.feral-heart.com/index.php?option=com_jfusion&Itemid=2&jfile=index.php&topic=15759.0)
Board (http://www.feral-heart.com/index.php?option=com_jfusion&Itemid=2&jfile=index.php&board=86.0) where you can find items and other creations.
First of all, you should find a map to download. There's a board (http://www.feral-heart.com/index.php?option=com_jfusion&Itemid=2&jfile=index.php&board=21.0) for public maps. You can also google to find some.
I suggest having WinRAR so that you can extract the files into the Export folder.
There's a video above that explains how it's done.
http://www.youtube.com/watch?v=1ULvvPVJIk0&feature=related (http://www.youtube.com/watch?v=1ULvvPVJIk0&feature=related)