There are a couple of factors that need to be known.  First of all do you have any basic martial art background and if so, how much?  Also, keep in mind that XMA is more than just tricking.  Actually if you look at the XMA program, tricking isn't so much part of the curriculum.  There are certain combinations that you need to learn as well as how to combine your combinations to make a good form.  Just like anything it is always good to start from the bottom and work your way up.  If you quick then you can just blow through the basics and get to the "advance" stuff quicker.  However, if you don't have a grasp on the basics, regardless of how many cool flips you can do, it will all still look like crap.

Keep in mind that if you were learning all your tricks by yourself, it is still good to get some people who have been doing tricking and XMA for a while to take a look at your stuff to see if you can improve on it.  Hope this helps.

If you can, I would recommend Camp Chat, Sharkey's Summer Camp or Boot Camp.  They would all be ideal in getting the help and advise you need for tricks.