It will be interesting to see what sort of education Charlotte and Louis receive, and whether they will be expected to find careers for themselves. Charlotte is slightly different since she's a girl, but Louis will possibly have to knuckle down and get a profession or job or make a real career in the armed forces
Andrew had a real career in the Armed Forces. It's not preventative of being an arse!
I expect the Wales DC will have similar education to their parents - they're already at a prep school, they'll probably board from 13+ and will then go to university and study something that genuinely interests them (without having to worry about how "useful" the subject is). There may be gap years before/after university, and a spell in the Armed Forces is possible for any of the three - length of time they serve would depend on which bit they go in to, and whether they pass the exams to progress up the rank structure (Andrew did, Harry never took them). Then, I hope, the chance to work for a few years, even if that has to be balanced with the start of royal duties (like the Anglesey years for William)
Whether they continue with a career, or are part time plus duties, or become full time working royals will depend on their individual wishes balanced against what the Family Firm would like in terms of the numbers out and about.
The DC of the Princess Royal and (I assume) of the Edinburghs give some idea of the sorts of things that have been tried so far, for those who do no duties beyond occasionally turning up at the odd garden party, at Ascot, on the balcony (rare now, but there used to be bigger family groups), Sandringham church on Christmas Day, and the family births/marriages/deaths.