You really need to get a start on counting his carbs and matching the insulin to the meal. I can appreciate how difficult that can be only two weeks into this, I'm only 18 months diagnosed myself, but long term that is the way forward.
Also, is he typically quite active after dinner? Higher activity will increase insulin sensitivity and can cause those hypos, so if he runs around after dinner, you need to adjust the dose,
So 1) count the carbs, dose appropriately 2) when you've got that bit right, dose reductions for activity.
A bit further down the line, coem back and ask about basal testing as well, as that's all-important.
But don't worry, sound like you're doing great so far.