A mentor is typically someone who has been in the role before. You go to him for advice or they can give you their perspective/ experience about things
A coaching relationship is different. They hold space for you, ask questions to help you figure out what’s best for you.
Roles change faster than people, and executive tenures are often short. In cases of true rapid scale (a business that’s 3–10×ing every year), I tell people to expect leaders to last about 18 months. Let them surprise you by lasting longer, but don’t let it surprise you if it’s shorter.