How can I properly run Perl "one liner" command line scripts?

Try:

#!/usr/bin/perl
# This is a comment ~~~
# This script will be run as a Perl script
# since 'perl' isn't a keyword or function in Perl
# something like this must fail:
#
# perl -e 'print "Hello";' 
#
# The following should work.

print "Hello"; print " World\n";

Or, if you want your shell script to execute Perl code:

#!/bin/sh
# That's a Bash script ~~~
# It's just a command line in a file ...    

perl -e 'print "Hello World";' 

Background: #! is an interpreter directive.

When the command is executed, it is converted to an execution of the interpreter.

perl is not a valid command inside a Perl script. If you had named that file as a .sh script, and used #!/bin/bash on the shebang line, it would have worked, but it doesn't really make a lot of sense to write a bash file just to invoke Perl (why not invoke Perl directly?)

Since you mentioned you want to interact with the command line, I'll mention here that you can get at the command line options within Perl via the @ARGV array. (See perldoc perlvar.)