Where do I begin and how to I find a legitimate tutor?
I've done this kind of tutoring in the past. The way in which the clients found me was through a training center. Basically, the client went to a training center and explained their specific needs, much in the way that you did in your message. The training
center replied something along the lines of "sorry, none of our scheduled courses would accurately fit your needs, but we can get you in contact with an experienced trainer, and you can arrange some dedicated tutoring on the subjects that you require."
So I would suggest that you call a good training center in your area and explain your needs. Hopefully, they should be able to get you in contact with a local trainer.