I would first concentrate on keeping it alive for a few weeks at the very least, learn when to water, and when not to, make sure it gets lots of light all day, and a good humidity tray, and if you can post a picture on the gallery of this forum (with a note here saying you have) that would be a big help. If it's tiny now, it may either be because it's very young, or because it's a particular dwarf variety that will only get slightly larger over a long time. You want it to develop a mature look even if small, and that'll mean giving it a not much larger pot than it has now, for it to grow into, with a fast draining gritty (non peat based) mix. A bonsai pot can also come later on when you have some idea what you want the tree to look like eventually, and when you've done some reading on ficuses, bonsai and how to 'get' there - it's not a 3 step process by any means, and patience is the most important part right now. Do check out http://www.bonsaihunk.us/cultural.html to get an idea what's what.