Rather than trying to input a variable name, perhaps it might be simpler to input a hash key and store your data in a Hash-of-hashes:

use warnings;
use strict;
use Data::Dumper;

my %hoh = (
   cs101 => { joe => 80 },
   cs102 => { moe => 90 }
);

print "Choose which hash\n";
chomp (my $input = <STDIN>);

if (exists $hoh{$input}) {
   my %hash = %{ $hoh{$input} };   # dereference hash
   print Dumper(\%hash);
}
else {
   print "$input not found\n";
}

__END__

Choose which hash
cs101
$VAR1 = {
          'joe' => 80
        };
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