cpan Tk from a command prompt will fix the Tk issue.

The "standalone Windows .exe" bit is more of a problem. Perl is not a great fit for applications of that sort. There are tools like Cava Packager that wrap up a Perl script and whatever it needs into something that acts like a stand alone executable, but it can be a bit of work to get going nicely.

Asking here about specific issues is a good way to get back into the swing of Perl, and rfc's (request for comment) on modest chunks of code would be a good sanity check to see that you are on a good track (there is no one "right track" in Perl).