First thing almost everyone will tell you is to get Age Verified. ASC has a strict policy about not giving out information to anyone below 18. I read your other post and I know you are of age, but you'll have to prove it by meeting a local Age Verifier rep (look in the FAQ section to find a list of reps near you).
Once you are verified you'll get access to restricted parts of the forum that have information regarding local shops, websites, as well as retailers who are members of the forum and have a stockpile of goodies. You'll also get access to the 'for sale' section that will be the source of many good deals.
Second thing everyone will tell you is to NOT buy an unknown/cheapo brand gun. Save up a bit more and you'll be able to find a better one on the classifieds. It'll save you a lot of headaches. You may also be able to find a package on the classifieds for a good price that would get you started with a gun, magazines, accessories and even some gear.
You should also know that while prices will seem much lower on sites in the US or Asia, those guns wont make it past the border due to Canada's laws. Your only option is to buy locally or from canada-based retailers/sites.
As for paintball gear you can reuse, most of the gear like gloves/outerwear/mask/radio should all be reusable for airsoft games.
Read and research a lot. The FAQs section will give you a lot of info, and the other sections will give you a better idea of which guns would be ideal as starters.
H&K G36c (KWA) / Glock 18c (TM) / Kimber LAPD SWAT Custom (TM) / Mossberg M500 (ACM)