Hello WisDomSeeKer34, and welcome to the Monastery!

Since you want the message to repeat (if necessary), you need a loop. In this case, changing if to while is all you need. :-)

Update: It might be clearer to use until here rather than while — that allows you to write the condition in the form of a specification. Also, the loop and the calls to <STDIN> should be placed in the subroutine:

sub choose
{
    say "choose a number:
1
2
3
4
5
";
    my $choice = <STDIN>;

    until ($choice >= 1 && $choice <= 5)
    {
        say "You have chosen the wrong number";
        $choice = <STDIN>;
    }

    return $choice;
}
[download]

Hope that helps,