You'll need SOL in your account to fund the transactions, so be sure to make a deposit to fund your wallet
The easiest way to make sure you're sending funds to the correct account is by scanning a QR which is generated and provided by the app. Simply click the Scan QR button in the top right of the Phantom Wallet app.
This is as simple as hitting approve. This is your last opportunity to double check the public keys and make sure you're sending funds to the correct account.