How do I find a mentor that has lots of experience doing this stuff?
Online and also in person.

Somebody who knows what they are doing for a long time now.
Having a mentor is important because they give you a direction where you can go, but if you want a mentor to make you a million or billion that's not a good idea. Use a mentor to motivate you. I read an article that even if they don't have a mentor they make million through trading a stock and other investment by reading a BOOK and watching tutorial video, so why not to try that also.