In order to have your Magix programs available on your new computer you need to do the following:
Ensure you have the installer files for the programs on your new computer. If necessary, log in to your Magix account and redownload them to your new computer.
In MEP, open in turn, on your old laptop, each project which you wish to be able to use on your new computer and choose File>Backup copy>Copy project and media into folder (shortcut Alt+S). I would recommend one folder for each project. In Music Maker follow the same process but in this case the location of the "save" function is File>Backup>Save project and used media (shortcut Ctrl+Alt+S). Again, one folder per project.
Deactivate the installation of those programs on your old computer
Run the installer for each program on your new PC and register them on line. Check that each is running correctly and has fully updated (assuming you have a current subscription to the Update Service). Especially check that all additional content has been downloaded and installed.
In order to transfer existing projects you can either, transfer all the folders you created under point 2 to one or more USB Memory Sticks, dismount them from that computer and then plug them into your new computer and copy all the folders to your hard drive; or, transfer all those folders to an external USB hard drive, dismount it as before, then connect it to your new computer. In this latter case, it is entirely up to you whether you choose to copy the folders to your new hard drive or choose to access them from the external drive and so save a little space on your computer's internal hard drive.