If you are new to Bitcoin and cryptocurrencies, Coinbase is your best option. It is simple to set-up and allows you to easily buy Bitcoin, Bitcoin Cash, Ethereum and Litecoin with a debit card.
Note: In Canada, you cannot sell cryptocurrencies with Coinbase, if you want to do so, you should open an account with QuadrigaCX.
Quadriga Coin Exchange is the most reputable Canadian platform to buy and sell cryptocurencies. You can buy and sell large sums using bank transfers, interact or direct deposit.
Newer on the Canadian scene is Coinsquare. It has a nice user interface and you can buy and sell cryptocurriencies. They offer a larger variety of coins than Coinbase and Quadriga CX.