I noticed your "I'm still really new to Perl ..." so I'm guessing a CPAN contribution wasn't really what you were looking at. This makes the answer to "Is it okay for me to have an empty namespace (Roleplay) and go straight for Roleplay::Player or Roleplay::Goblin?" a more straightforward YES!

You can have these:

    /path/to/perl/mods/Roleplay/Player.pm
    /path/to/perl/mods/Roleplay/Goblin.pm
[download]

without needing to have this:

    /path/to/perl/mods/Roleplay.pm
[download]

You may still want a top-level Roleplay class but it's not a requirement of Perl.

In terms of tutorials, I'd suggest going to Perldoc and looking under GETTING HELP - Tutorials. perlboot, perltoot, perltooc and perlbot are all directly related to Perl OO programming. perlfaq2 - Obtaining and Learning about Perl lists many resources you'll probably find useful. Scrolling down a bit further, you'll see Reference Manual which links to a large amount of documentation including OO topics such as perlmod and perlobj. I recommend you bookmark Perldoc and refer to it often.

Regarding graphics, take a look at CPAN. The Graphics and User Interfaces sections should probably be your first ports of call.

You can post your code to, ask questions of and seek advice from PerlMonks at any time. Perlmonks FAQ describes how to do these things. In general, a clearly written question with examples of what you've already tried (including appropriate output, particularly error messages) will be far better received than a "it didn't work" or "please write this for me" type posting.