Delegate receives a reward each epoch, you can check it in the wallet, look at your stake account amount which you staked it should be higher. However, to check the rewards you can enter your stake account and scroll down till you'll see the Rewards Section. And there you'll see all the information about your rewards, how much was earned, which epoch etc.
Or use command-line tools:
velas stake-account <stake account address>
and it should show you the rewards + % of earnings, epochs, etc.