Book a centre seat against the bulk head and they have small cots that attach to the bulk head so you can put the baby in there when sleeping, they even had little mobiles to put on them and entertain the kid.
You can try and book these but they do allocate on need and I think they are more for the younger ones not toddlers, usual rules apply where they will rattle down some criteria to see who gets those ones. Downside of those is you get fixed armrests and TV is pull out so as said not as good for stretching out sideways.
Staffing levels and help will depends a lot on the timing of the flight, a lot of the ones up from Oz try and do a night flight so the staff do dinner and hit the lights ASAP, can’t remember how it works the other way – but when that happens the staff do wind it down a bit and head for the crew areas.