Here is the (untested) rest of your program.

Please reference the perl documentation for constructs you have trouble with.

$/="\n\n";                    # Set the record separator to be 2 newli
+nes
my $sportfile="my.sport.txt"; # Or whatever the file name is
open (my $sport, "<", $sportfile) or die "Cannot open $sportfile : $!"
+;

while (defined <$sport>){
  next if m/\b$first_name\b.+$last_name\b/;
  print;
}
close $sport;
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Output will print to STDOUT. This can be directed to a file.
Update:Corrected "close $sportfile" to "close $sport;"