Im glad your open minded and willing to learn, here on the ASC forums we really respect those who are open to suggestion and can stand a little criticism. Airsoft in Canada, as it stands right now sits in somewhat of a greyish area. So there is alot of information to absorb and not all of it can be spooned in the brain in one sitting.
I hope that Well p90 was ordered in Canada. Ordering from anywhere else is bad news. As per Canada's firearms regulations, the Canadian border service will seize your gun and destroy it and you will be left with nothing. Unless that gun is made of clear plastic material, then there maybe a chance that you culd recieve it. Im not going to get into a debate of whether or not clear guns can make it. Some say yes, some say no, I dont with to dig for evidence to support either side. Some companys in the US and abroad will tell you that they ship to Canada with no issues, but in reality that is most likly not true and they just want your money.
The short and sweet of it is, skim through this section and read some of the threads. You'll find alot of info that may help you with any questions you may have now or later on.
http://www.airsoftcanada.com/forumdisplay.php?f=21