Hi
To check whether an email or message is, in fact, from Apple, follow Apple's instructions here:
- Identifying fraudulent "phishing" email - Apple Support
- Identifying legitimate emails from the iTunes Store - Apple Support
If you have an opened a phishing email or message (which is designed to trick you into disclosing personal information such as your Apple ID, password and/or payment details to a third-party), then you should not reply to it, visit any linked website or enter any information there.
If you have already entered any information into a phishing website or otherwise provided the sender with any information - or if you are concerned that your Apple ID may have been compromised - then be sure to follow the steps here:
If you think your Apple ID has been compromised - Apple Support
If you need further assistance, contact Apple Support:
Contact Apple for help with Apple ID account security - Apple Support
To report phishing attempts to Apple, follow the instructions here: