Advice needed for in-house coaching

Hi there! I please need some advice on in-house coaching, as this is something we are looking to roll out (GROW model).

What in-session coaching activities can I use with a customer services team manager to improve manager performance, and ultimately their teams performance?

Also what out of session activities would you suggest?

If there are weaknesses in the team, how would I approach the coaching? Best practice states that the coachee (the team manager) should identify the weakness that they want to develop, however what if there are business priorities?

Should team manager coaching sessions focus on coaching them as an individual, and also training them to coach their own team?

Many thanks