The way I have found mentors is by starting with taking lessons in a skill from people, which establishes the necessary boundaries in the relationship. If they are the best at what they do, mentoring becomes the effect of the relationship itself, since mastery above the skill is what you are learning.
Mentoring someone means sharing the right experience at the right time, which means you have to be around to do it, so it's less of a transaction than a way of relating, but it can start with the lessons/transaction based relationship.
Great question. Find someone in your skillset, hobby, industry or knowledge domain that has been doing it longer (preferably much longer) than you. Don't think because you are a lone wolf that there aren't others like you. They are out there and they would love to share with you. Also you can establish the boundaries of your mentor relationship. You can meet and set the frequency at your own choosing.
I really want to find a mentor but not sure where to even begin.