Can I send Bitcoin to my Coinzai address?
No, as they are different Digital currencies on separate Blockchains. As such each Currency has its own designated wallet.
Where can I buy Bitcoin?
Bitcoin can be purchased online from a Bitcoin exchange, Coinbase is a popular exchange with reasonable fees. They cover most of Europe, America, Australia and Singapore. A list of the countries that they support can be found here: https://www.coinbase.com/global?locale=en
If your country is not supported by coinbase you can buy Bitcoin at coinmama. They are currently operating in 226 countries and a list of which can be found at (https://support.coinmama.com/hc/en-us/articles/211237889-Areas-we-operate-in)
Chinese citizens can purchase Bitcoin from OKcoin. Which is the largest Chinese Bitcoin Exchange.
Japanese citizens can purchase Bitcoin from Coincheck.
South Korean citizens can purchase Bitcoin from Coinplug an exchange that operates the okBitcard service which allows Bitcoin vouchers to be purchased from any 7-11, Mini Stop or Nautilus ATM across South Korea.