Where can I find a mentor to learn about real estate micro flipping from?

The ones that are successful have hundreds of thousands in capital and are dealing on a cash basis.  There are investment clubs and courses taught by realtors who are also investors.  There are books & courses that teach a lot of things. But realistically, without capital you are unlikely to have much success.

I've known a couple of guys who had 10-20 rental homes. But they require 20% down and good credit.

I knew another guy who tried it and made some money but he said the learning curve was steep.

And again, he was using cash, not debt.

I was going to look into about 15 years ago but never did it partially because I just did not want the headaches. 

The realtor I used to buy my house taught some kind of a course where he taught investors. He taught them to be able to make money either flipping it or renting it out.

Find someone flipping houses and go work for them.  They aren't going to train you to be their competitor...

You can't. People want to make money for themselves, not to "mentor" someone trying to learn how to do it.

I reccomend starting by reading a few books on real estate investing.  There are so many good ones that I'm not going to bother with any reccomendations.  If you could find the right mentor that would be great but real estate investors don't usually want to mentor and looking for a mentor might not be a great use of your time.  Consider the people who wrote the books as your mentors and go read a few books on real estate investing.

The biggest mistake rookie flippers make is not knowing the market.  They will by a home for $X, spend $Y fixing it up only to find out it's not worth $X plus $Y plus profit.

Learn how to determine the ARV (after repair value) of a home.  Find a good, knowledgeable Realtor.

There isn't a flipper in the world who is going to take his time to teach you how to flip houses, when he can use that time to flip a house himself.

Flipping is a suckers game. You can work your buns off and risk a lot of money and the real estate agent will end up making a lot more than you.

you could try advertising somewheres and asking for one