Hey there Sopheapmen,
It sounds like you need to find out what your Apple ID is. I recommend the following article to help you find your Apple ID named:
Apple ID: How to find your Apple ID
An Apple ID is your username for everything you do with Apple: shopping the iTunes store, signing in to iCloud, buying an app, using iMessage, and more. That's why it's best to use a single Apple ID and not forget it. Using multiple Apple IDs might be confusing and may cause issues with accessing purchased content or using some services.
If you can't remember your Apple ID, follow these steps to look for it:
- Go to My Apple ID (appleid.apple.com) and click “Find your Apple ID”.
- Enter your first name, last name, current email address, and any prior email addresses that you might have used to create an Apple ID. Apple uses this information to search for Apple IDs.
- If no Apple IDs are found, follow the onscreen instructions to create an Apple ID.
- If one Apple ID is found, choose whether to receive an email from Apple or answer security questions. Both options will conclude by asking you to reset your Apple ID password. Follow the instructions provided.
- If multiple Apple IDs are found, select the one that matches your current email address. Then choose whether to receive an email from Apple or answer security questions. Both options will conclude by asking you to reset your Apple ID password. Follow the instructions provided.
Thank you for using Apple Support Communities.