use strict;
use warnings;

my ($file, $handle, @arr);

open($handle, 'test.txt');

BREAKPOINT:
while (<$handle>) {
    if (m/Here starts the second paragraph/) {
        chomp;
        push @arr, $_ for split /\s+/, $_;
        while (<$handle>) {
            chomp;
            last BREAKPOINT if !$_;
            push @arr, $_ for split /\s+/, $_;
        }
    }
}

print join "\n", @arr;