Emma Bostian launched codingcoach.io, a free, open-source project that connects mentees with mentors. Emma discusses how she launched Coding Coach before she had a real database. It's better to have your product out there than to sit on it until it's perfect, you can always iterate.
Mentoring doesn't just help others, you improve your teaching skills, and it also just looks good to be a mentor.
Mentees should respect a mentor's time since they are doing it for free. When asking someone to be your mentor briefly describe where you're currently at, and some tangible goals that you want to work towards.
Mentorship doesn't strictly have to be a one-on-one relationship with someone. You can mentor people through content creation as well. Blogging, recording videos, writing books, and giving talks all teach people.
Often people's goal with their mentor is to be ready for the technical interview. Many companies are wising up to the fact that someone's ability to write algorithms doesn't correlate with their expertise as a front-end developer.