Every retailer in Canada (US/EU/AU) needs a business registration number (and sometimes Permits) in order to trade or sell.
There are plenty of retailers that approach wholesalers and manufacturers. You need to realize it costs a wholesaler time and money to set up an account. If you seem like you won't be a profitable distributor, they'll probably turn you down. You will have to prove to a potential supplier that you are a serious buyer who will respect the supplier's time and who expects similar treatment in return.
When contacting a supplier (for example by mail) make sure you mention your business registration number. Be sure that your emails use proper grammar and are spellchecked. Nothing looks more amateurish than an email that's poorly written with bad grammar or spelling.