Secure & Share PDF with Comments

I need a professional, ideally a paralegal, who can teach me, in an hour or so how to

Protect a PDF with password protection,
Share it via a direct download link,
Allow designated people to make comments.

The PDF should also have the capability for signatures.

Ideal skills and experience:
- Proficiency in PDF software
- Experience with document security
- Familiarity with setting up shared links
- Knowledge of enabling comment and signature features