Mentorship is a very trust-based relationship. It is one of guidance and governance. It's not like coaching, which is prescriptive and deliberate. So, you need to be careful about who you choose to mentor you. I would get to know them well before you call them a mentor. I would also make sure that you trust them and they trust you. As you can imagine, it can get quite expensive paying several mentors for their time to try to build these relationships. If you can, build the relationship first, before paying any money. You can eventually get to a paid relationship (fees or equity) if it is beneficial to you. Keep in mind that good mentors can also become good board members, and you will compensate those roles.