This is one of those pfb things a bit.
My (dd) first didn't have any chocolate AT ALL until 2, then only a teeny bit and only at parties when unavoidable.
My ds2 has had chocolate and ckaes and ice cream he's 20 months, or
I think this...
We restrict sweets (meaning non-chocoalte sugar gummy bears/marshmellows etc) they don't get them unless randomly given them at parties. We don't buy they aren't in house.
We do buy ice cream and approx once a week they get knickerbockerglories (fruit and icream in a tall glass to thee and me).
I think sweets/chocolate bars at school age restricted to once a week pocket money time.
Puddings once a week ish ice cream otherwise other stuff like yoghurts and custard and jelly.
They get chocolate randomly and rarely - they don't expect it they go ooooooh when given its that rare.
Weaning son. hmm. well as your dd gets bigger she'll be after his sweets so you might encourage him to scoff straight away which is better for his teeth. All in one rather than over a longer period.
Or get him into a magazine so he spends pocket monety on thart.