There are quite a few posts here in the forums with suggestions from experienced signing agents on how to get business - have you taken a look at those? You will get a lot of good information from the perspective of many different experienced people by looking at the answers that have already been provided for this question.
Also, finding a local mentor may not be easy, you are basically asking another notary in your area to spend their time training you to be their competition. I have personally only mentored / trained 2 notaries to be signing agents and that was because I have enough business from a builder that it would benefit me to have someone to subcontract to (I make money off of the signings that they do). One of the ladies is a Spanish speaker, which meant I could now make money subcontracting her to do signings that I wasn't able to do before because of the language issue. The other lady only wanted to do this part time to make a little money on the side so she only does the deals that I send her. She is not interested in going out and getting any other business so I knew she would always be available for the deals I needed her to do.
Honestly, if there was no financial gain in it for me I wouldn't spend my time mentoring / training someone. It may sound harsh, but it's the truth.