You can start coping pure perl modules to the appropriate places, however this can be a time consuming thing. Say you want to install a fictitious module ACME::Shazam, which you know to be pure perl, you could just copy the files to correct locations, then run some example code which makes use of the module. But, whoops, ACME::Shazam has 10 dependencies, none of which you have two of which are witting in C. It would have been a lot quicker and a much less effort if you used the CPAN client to do this for you.

"when I read that it wasn't clear to me that some modules just contain perl code which can simply be copied to the appropriate location whereas some contain C code which may need to be compiled."

The tutorial I linked to has a section "Installing Modules that include elements coded in C". I appreciate that there may be a lot to read/learn at first, but stick with it, explain what's confusing you as clearly as possible and people can help.

"When i read it I didn't understand why it started talking about C compilers. I just assumed that was something to do with linux I didn't understand"

This isn't a linux specific thing, Microsoft Platforms have the same issue.