How can I say Coaching in plural?

The word “courses” should work instead of “coachings”? Coachings seems incorrect.

A coach can provide multiple trainings. Or A coach can train multiple teams or players.

A Google Books search shows many instances of "coachings" that imply the use of "coaching" to denote an individual coaching tip or session. While I hadn't encountered this before, it seems established.

The object phrase "multiple of coaching(s)" is not proper and is awkward. A different phrase would convey the intended meaning correctly such as "in multiple areas", "in multiple disciplines" or just "multiple subjects" as three examples.

However, if you want to convey multiple groups, people, or teams, then use these similarly as object(s) to be coached. If you wish to express "multiple coaching sessions", then that phrase could be used for that purpose.