perlintro#Files-and-I/O has documentation on how to open a file for input, and how to read from a file. Your assignment also shows the example, "$line = <TEST-INPUT>;", which will work to read a line from the file with one exception: Filehandles, like other identifiers in Perl shouldn't have a hyphen in them. Remove that hyphen and it becomes a valid identifier for a filehandle. Just make sure that your open opens the filehandle first.

perlintro#Basic-syntax-overview shows how print can be used to print a string literal. perlintro#Perl-variable-types shows how to print a variable, such as $line.