Hi again. I take it you've read the multiple posts on getting rid of the training wheels on the family and recreation section.

In short, pedals off, seat low enough for him to get his feet on the ground comfortably, then scoot along until he can keep his feet off the ground and balance/steer. Useful if there is a slope he can roll down on to a level bit. Then replace the pedals and your troubles will really start.

We teach 40/50 kids a year to ride using this well-tried method.

Re the LAB courses: the best age to teach kids this kind of thing is from about 9 upwards, when their capacity to judge speed and likely intentions of other road users is developing. In the meantime, use what you might learn on such a course on an incremental basis as he gets older and more skilled. By the time he's ready to take it himself, you should have instilled enough good habits in him that he'll sail tho' it.