I spent...six years learning to drive. I drove really really well, too, although couldn't find my way anywhere for toffee.
Took my theory twice (100% both times, but the first expired). Took my practical four times. Failed every go on one serious although no dangerous and not many driving faults. This was because the moment the test started I suddenly forgot even the most basic rules of driving and unconsciously self-sabotaged until I knew I'd failed...at which point I drove fine. Sigh.
I gave up.
I'm autistic, so have issues with practical coordination and navigation, and I'm putting it down to that although it may just be I'm a crappy driver. >.>. I swear I've never done anything (including flying abroad alone for the first time) as frightening as a driving test in my life before and I pray I never have to again.
Buses for me from now on...
In answer to the question, though, I think I'd had ten or twelve lessons before my instructor took me out of the industrial estate and out on the actual road...though inside the industrial estate there was still traffic and roads. That would imply from lesson 1.
I've driven with my parents as well, and quite a lot...but it's up to your instructor when they think you can handle going out on a proper busy road.