First of all, good call on converting over to airsoft!! Second, like stated above you will have a 99.9% chance of NOT playing at any fields in canada. Most of us here dont even condone the use of airsoft under the age of 18.
So, welcome to the site, there is tons and I meas TONS of info on here. Do a little research, and get to know some of the people and maybe by the time you are 16 you could maybe play at a local field.
EDIT: on a side note, dont get a sniper rifle as a starter. Go for an assault rifle or submachine (ie. MP5)