Stop using two of them.
Maybe switch the passwords. Maybe.
There is no means to migrate purchases and content among Apple IDs, though your own data can be moved with some effort. (Here is one of various discussions of relocating user content. Again, any purchases, media, and subscriptions cannot be moved.)
Don’t delete the Apple IDs until you’re well and truly sure they’re not being used somewhere. And maybe not even deleting them then.
Why? These Apple ID “deletion” threads too often end badly, when some now-deleted Apple ID is used for, for instance, Activation Lock on some forgotten device.