Japanese has three related conjugations that change who is doing what to whom: the passive (something was done to you), the causative (you made or let someone do something), and the causative-passive (you were made to do something, usually against your wish). They share a conjugation pattern, which makes them easier to learn together than separately.
All three attach to the same verb stem used for negative-form conjugation, the "a-row" stem. If you can already conjugate a verb into its negative form, you already know the stem this guide builds from.