Firstly, "isn't working" is a totally inadequate error report: you need to post the error messages you are getting. If you're not getting any error messages, add use strict; and use warnings; near the start of your code. If you don't understand the messages, also add use diagnostics; for more verbose messages.

Here's the basic syntax for pushing onto a simple and a complex array:

# simple array
push @simple_array, $array_element;
my $simple_arrayref = \@simple_array;
push @{ $simple_arrayref }, $array_element;
# complex array
push @{ $complex_arrayref }, $array_element;
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You'll note the absence of any ->[] in the above code.

You have another problem in your push line above. Compare how you've written $self{"Course(s)"} here with how you've written it everywhere else.

I hope that's enough for you to resolve the problem yourself. If not, post your error messages and describe what parts you're having difficulty with.

Finally, there's all sorts of problems with your example push:

$self->{"Course(s)"}=[<STDIN>]
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• It's an assignment, not a push.
• You'd probably need [scalar <STDIN>] instead of [<STDIN>]
• Your data will contain all the newlines that the user entered.

Something like the following skeleton code would be better:

while (<>) {
    chomp;
    push @array, $_;
}
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