Account Migration has not begun. There will be an in game message when it's your turn to move. Do not fall for any third party websites that are telling you to migrate NOW. They're trying to steal your information.

Hi, I'm having issues getting my little cousin signed into a java edition account I bought for her about two years ago I know the username however I've forgotten the email and can't get the proof of purchase as I had used cash and threw the card away after activating the account.