PROBLEM: A few weeks ago, my iPhone 6Plus started with ghost mode. I entered my password, which was over-ridden by The Ghost. Eventually I was locked-out and instructed to connect to iTunes. But that would have erased my phone. iTunes instructs

PROBLEM: A few weeks ago, my iPhone 6Plus started with ghost mode. I entered my password, which was over-ridden by The Ghost. Eventually I was locked-out and instructed to connect to iTunes. But that would have erased my phone. 

iTunes instructs me to get my back-up from the cloud and install on my new iPhone 13. 

I don’t understand; Apple has been notifying me forever that nothing is being backed-up because my ‘free’ storage is filled-up and so I would need to spend cash for additional monthly storage. Being retired, on a fixed-income, this is not an option. 

I need to transfer the info from iPhone 6 Plus to my new iPhone 13! 

Thanks.