The fact that you have been running glow engines already is a huge bonus. Getting your engine running properly is a big part of learning, one that most instructors skim over (which results in a beginner having to contend with deadsticks when they land - not a great thing). That plus the fact that you're used to the orientation thing (driving at yourself and not turning the wrong way), is also a good thing.

That being said, flying is considerably different than driving. I taught myself how to fly using a relatively slow parkflyer before moving onto a faster glow trainer. This route worked for me since I was able to "solo" my Avistar on my first time at the sticks, and I flew loops, rolls and even a couple of Immelmans on the second and third flights. I think that the most important attitude that any beginner should have is be honest with yourself. If you need help or practice, ask. Most of the people involved in this hobby are very helpful.

Instructors by and large instruct because they love the hobby. I haven't met one yet who didn't really want to teach someone else how to fly(there are exceptions, I just haven't met one). Most are very competent flyer with years of experience, but they do all have personalities that go along with the teaching. I'd say call a couple of instructors in a club and see if you "hit it off" with any of them. If you do, you'll have your instructor.

Probably the most important thing is to have fun. This is a hobby after all...