Great Fox403, what is your proposal - Free labour for free tuition, available what day or days of the week.
Just outline your basic proposal and the rest is a case for negotiation with prospective mentees.
Find someone with a lot of work to do and you will be given free fitness training, lifting lots of heavy boxes and if you have your wits about you and a pleasing disposition, then you will get to ask all the questions that you can think about. You will get a lot of experience too. As you prove your worth, then you will get to enjoy the company and the work as you learn.
No one says that it will be easy though.