Native English speaker (British English) The child has to get used to school (in general, i.e. sitting still and listening to a teacher).
The child has to get used to THE school The child has to get used to HIS/HER school (The child has probably adjusted to school previously but has maybe started a new school or other changes) I don't think that there is much difference in terms of English but the former implies that the school is new to the child (not yet their school) while the latter is slightly odd as one rarely needs to get used to something which is one's own, but I don't think it is really noticeable unless you think about it too long!
Neither. When the verb "привыкнуть" if followed by a noun, a noun-like pronoun or a nominal phrase, it needs "к", just like "get used" needs "to":
- Я не знаю, привыкну ли я когда-либо к Порту. I don't know if I'll ever get used to Porto.
- Я не могу привыкнуть к тому, что надо вставать в 6 утра. I can't get used to the fact I need to get up at 6 in the morning.
- Я так привык к коту своего соседа, что не хотел из-за него переезжать. I got used to my flatmate's cat so much that I didn't want to move flats because of him.
However, if it's followed by an infinitive, you don't use "к":
- Я привыкла ходить в это кафе. I got used to going to this cafe.
The audio and the pronunciation of this gentleman are extremely unintelligeble. I mean this in general. It might correspond to some kind of pronunciation how some russians speak. But for studying I consider it inappropriate. The audio itself in his case is very often of the worst quality.
No, stress is on «привы́кнуть», where it should be. Although this pronounciation doesn’t sound too natural.
Once again, the audio might as well be thrown out, it is so bad and so useless. Beginners and even intermediates students trying to reproduce the sounds of the audio would just be making a lot of noises which might or might not (probably not) be understandable by a native speaker.
Most of the course is a waste of time in learning how to speak anything more than rudimentary Russian. It's a joke.