I sounds like when i started out.
he won't wet the bed (i have been trying for years, still not happened) the closest is to goto bed in a wet diaper.
tell him to put on about an hour or so before bed, when he feels he needs to go. sit down on the toilet.
sounds weird but it works. the rest comes with will power and practice.
hardest job i had was whenever i thought about peeing i got an erection, that just doesn't work.