Select them, confirm the transaction, and you're done - you are now nominating. Your nominations will become active in the next era. Eras last 1 hour in Cherry Testnet Network. Depending on when you do this, your nominations may become active almost immediately, or you may have to wait almost the entire 1 hour before your nominations are active. You can check how far along Cherry is in the current era on the ”Staking Page”. Assuming at least one of your nominations ends up in the active validator set, you will start to get rewards allocated to you. In order to claim them (i.e., add them to your account), you must manually claim them.