Has anyone had experience being or hosting an au pair in the United States?

I finish year 12 in Tasmania, Australia in November of this year and my aunt and uncle have mentioned some people they know who live in Albany, New York who could potentially find me a family for whom I could be an au pair next year. I have applied for university in Australia but could defer for the year.

But being an au pair for a year in the US, does that mean through the school year? Like September to June or whatever it is? Because the university semester in Australia starts in February which I would have to be back for the following year, so am I able to go from the start of next year to the end of next year?

Does it matter that I won’t be studying in the US?
If I don’t turn 18 until April next year does that mean I can’t be an au pair until then? And If I started then would I have to go through until April the next year or could I cut it short to be back for start of semester in February?

If I get there and decide to apply for university in the states, how long could I stay with the family?

Any other information and personal stories would be greatly appreciated.