Can I have two accounts on one email

I need to change my apple id email but when i try to it says "already an apple id" I went to the old id and tryed to delete it but i saw you cant delete an id .so now i'm stuck with ,my normal id with all my data and old email, and an old one with no data with my new email😠 so i need any way to use my normal id with my new email unless i can transfer all my data from one account to another?