When system will generate your personal ETH deposit address you may want to deposit some coins to it. Peatio recommends Rinkeby Ethereum Testnet.
To get test coins in Rinkeby network do the following:
1) Generate your deposit address. 2) Copy it. 3) Open Rinkeby faucet. 4) Read paragraph «How does this work?». 5) Follow the guide you have just read. 6) Wait until transaction will receive enough confirmations. Then you will see your balance at «Funds». You can use block explorer to track the status of your transaction.
To get ETH in Kovan network you will need GitHub account. Go to https://gitter.im/kovan-testnet/faucet, sign in and post message with your ETH address. In few minutes you will get money automatically. Don't post too often or you can be banned.