haukex has already provided mind-bogglingly excellent answers to each of your ten questions. As a starting point, I suggest you start with his sample MyPackage given at the end of his reply, and then gradually flesh it out, learning as you go. Feel free to post early versions here for feedback.

As time permits, you might also like to browse through my humungous Writing Solid CPAN Modules looking for any topics that you have a special interest in.

I still remember the steep learning curve when writing my first Perl module. Lots to learn, but very rewarding. Good luck with your first Perl module!