. . . . when I was installling photo manager I noticed all my files were being uploaded to the cloud. How do I manage my data that was transferred . . . .
What indications were there that Photo Manager was uploading to the Cloud, and where was it uploading to?
I suspect what you were seeing was the Magix Connect being installed and the dialog that tells you what it does while it is being installed.
PhotoManager has no Cloud uploading functionality, it can only import/download from the Google Drive or Microsoft One Drive, and you have to select this and give account details from whichever you are importing from.
. . . . I was installing photo manager a notice came up indicating my files were being uploaded . . . .
Installation is a 3 step process - first the Download Manager (4.5MB), running this downloads the actual program (415 MB) before the full installation starts - I suspect it is this dialog and the download progress bar is what you are seeing.