What is the best way to transfer all my Files and Data from the old computer to the new one.
Transferring your files is easy. Programs can't be transferred - they have to be reinstalled on the new computer, and to do that you need to have the original installer and registration information. There is no supported method to transfer a program from one computer to another. In addition, you should only reinstall programs that are supported on Windows 11.
You can certainly try to reinstall unsupported programs. There's no harm done, but also no guarantee that they'll work properly in Windows 11, and neither the developer nor Microsoft will be able to help you if you run into problems.
In my opinion: It makes no sense to waste a factory-fresh Windows installation, along with the computer's warranty and access to the manufacturer's technical support, by over-writing it with a clone of an older computer.
To transfer your files:
First, be sure that all your personal files are located inside the folders that Microsoft intended to hold your personal files, i.e.:
C:\Users<your user account>\Desktop, Documents, Downloads, Music, Pictures, Videos
then copy these folders to an external hard drive or a USB flash drive. (The reason for copying rather than moving is that in case anything bad happens while you are transferring your files, the originals are preserved.) Then move the contents of the folders on the external drive to the corresponding folders in Windows 11.
Be sure to include user files that are not where you expect them to be. For example: If you're an Office Outlook user, be sure to have a copy of your .pst file in your \Documents folder.