while (my $data = $ss->getNextRow()) {
   # skip lines until we find column header "Last Name" in first column
   next if $data[0] eq 'Last Name';

   ... stuff ...
}

##</code><code>##

while (my $data = $ss->getNextRow()) {
   # skip lines until we find a non-blank row
   next unless grep { ! /^\s+$/ } @$data;

   ... stuff ...
}

##</code><code>##

while (my $data = $ss->getNextRow()) {
   # skip lines unless they have the right number of columns
   next unless $expected_columns == @$data;

   ... stuff ...
}