I don't believe that suggesting a language will help you out. You need to learn how to program to become a programmer. I can, however, suggest several books that can help you with that goal, and help you pick up a few languages along the way.
These books should give you a solid enough foundation that you should be able to handle any computing problem. Also, they are full of exercises that you can use to learn any language you wish while going through the books.
If you are serious about learning the Perl internals, and extending Perl, then I would suggest the following in addition to the above books.