To make a deposit, go to "Wallet" through the main menu or plus icon in "Account details".
Click on the deposit button for the cryptocurrency you are about to deposit.
Select one of the payment channels.
Send funds from your wallet to the displayed address. As simple as that!
The deposit logic is the same for other cryptocurrencies.
To start trading P2P contracts, move funds from your wallet to one of your trading accounts using the internal transfer ('Transfer' button).