You sent bitcoins to an address in a wallet you haven't set up yet? That sounds impossible. Where did you get the address? All you need is the private key. You can import that into any wallet.
Where do I get the private key?
Each public key (adress that you have) have it's Private key so it's impossible saying that you sent coins to a adress that dosen't have private keys , I don't think it's possible to send coins to Adress that dosen't exists yet . Have you checked any blockchain explorer website to see really if you sent the coins ?