Google applications, such as Play Store, require a Google account, and Samsung Apps requires a Samsung account. Create Google and Samsung accounts to have the best experience with Galaxy S4.
Follow the instructions that appear when opening a Google application without signing in to set up a Google account.
To sign in with or sign up for a Google account, on the Applications screen, tap Settings → Accounts → Add account → Google. After that, tap New to sign up, or tap Existing, and then follow on-screen instructions to complete the account setup. More than one Google account can be used on the device.
Set up a Samsung account as well.
On the Applications screen, tap Settings → Accounts, select an account name under My accounts, select the account to remove, and then tap Remove account.