I think generally in Primary, children don't attend and in Secondary they increasingly do, especially once options are being chosen.
The Q 'how do you think you are doing' isn't a lazy question, nor the start of interrogation. It is an acknowledgement that the child is there and is of course involved in their own learning. Most children are not very forthcoming, but have had a chance to say something and then the teacher moves on. Others are pretty insightful, which can spark a conversation.
Regardless, the teacher will have things they want to say and will say. Often they will speak to both parents and child and talk about specific topics covered which will be meaningful to the child, if not the parent.
So a good session with parent and child there will include a summary of general progress, plus some specifics about the syllabus which parents may not be fully au fait with. There will be some target giving/areas to work on too. There may be discussion with the child about levels of application/effort etc. these are useful too, because a teacher may ask the child how far they are willing to work harder. The teacher,parent and child knows all of the above have heard their answer and will be held to it.
Also useful to have pupils there too, so they hear 'from the donkeys mouth' as too many parents only hear or report back negatives and others only hear and report back positives.
As a parent, I would ask about absolute levels of attainment....what my child has achieved, whether this is NC levels or GCSE standard work. I would also ask what the teacher thinks they are capable of by the end of the year or course. And I would ask for a couple of specific things for them to work on to help them get there. I would write it down, as I know it is hard to remember after the event. Sometimes I might also ask if my child is holding thi pier own in the class, esp if it is a set....ie so are they are the bottom of their set,mor doing comfortably within it, or is moving up a possibility.
I would also ask if they felt my child was pushing themselves or coasting.
Of course I would listen first and much of this might be covered I. What the teacher has to say, without any need to ask.
If there is anything they cannot answer, I would ask them to get back to me about it ......give it a week to 10 days, and then follow up if there is no contact.
And if you need more than the allotted time, don't make the whole evening run late, but arrange to see the teacher another time.