To use CryptoCanvas, you will need to install MetaMask, a browser extension, which connects your browser to the Ethereum network. You will also need to put some free Test Ether in it to play with the canvases.
Download MetaMask on the Official MetaMask Website.
Because this is a BETA version, connect your MetaMask to Rinkeby Test Network instead of Main Network.
Ether cryptocurrency (ETH) fuels all the operations performed on the Ethereum network. In live version of CryptoCanvas you will need a small amount of Ether to make operations such as painting, making bids and trading canvases.
BETA version uses Test Ether instead, because it's running on the Test Network.
You can get Test Ether completely free.
To get Test Ether: