Do I have to follow all the modules in numeric order (1, 2, 3…)?
No, you can follow the modules in random order whenever they suit your work calendar. So you can start with module 3 if that one comes first in your timing, and then follow module 1 and 2 at a later time, etc. The modules are all stand-alone course modules; you can step into the CISO track at any module and then follow the other modules according to the frequency with which they are organized.
The only exception to this rule is module 7 (the master project), which can only be started once the complete set of modules 1 to 6 has been completed. You have a period of 2 years to complete the full trajectory.