I don’t expect 5.3.0 to work correctly on a new silicon Mac so I would delete 5.3.0 from the new machine.  If you need to continue to do work with and/or verify results with 5.3.0, then continue to run it on your old Intel Mac.

Unfortunately, the video you watched is somewhat out of date; it may not work on a silicon Mac with a newer version of MacOS to launch freeview via the Finder so you should try the command line instead (see below).

The most recent info on Freesurfer updates is on,

https://surfer.nmr.mgh.harvard.edu/fswiki/rel7downloads

In the section describing the 8.1.0 release, the “here” link for setup information points to,

https://surfer.nmr.mgh.harvard.edu/fswiki/rel7downloads/rel8notes

You should setup your license file to be found in the shell environment via the FS_LICENSE environment variable as described in the 1st section SEETUP FREESURFER LICENSE

The section further down the page in SETUP A MATLAB DISTRIBUTION for MACOS lists how you should set the freesurfer environment.  Please try running the bash shell as listed, and I’ve essentially listed all that below.  Once the bash shell output resembles the below, try running freeview from the command line.

- R.

- - - - - -

…. create a new terminal window and run the bash shell … in the output below the users home directory ($HOME) is /Users/me ...

You can ignore any notifications about methods/classes w.r.t window functions.