Finding an app or file?
You can use locate to see where a Perl binary is installed

locate bin\/perl  | grep perl\$


for example

$ locate bin\/perl  | grep perl\$
/Users/corti/perl5/perlbrew/perls/5.20/bin/perl
/Users/corti/perl5/perlbrew/perls/5.20t/bin/perl
/opt/local/bin/perl
/usr/bin/perl


By the way, I would strongly suggest to use Perlbrew to install an additional Perl version.