All schools, no matter where you are, vary.
Whether that be private school or public school.
Meeting the Teacher night, for me, is important.
On those nights, you meet the Teacher and also the Teacher or grade level, explains to the parents, about what the kids will learn, what their expectations are and the curriculum, and about the school, etc. At least, that is how it is at my kids' school. And the parents can ask questions too.
I take my kids to school, and walk them to class, (most parents do that where my kids go to school), and you go into the class, help the child get their things out and say hi to the Teacher and what not. The Teachers welcome that. They have no problem with parents coming to the classroom. That is how it is at my kids' school.
Per my kids' school, there is no bus, that drives them.
Hence the parents take their kids to school.
If you go to the school and the "meet the Teacher night", then you will know what the school's routines are.... and you can ask questions. This is the time and place to see and find out about all of that.
Per lunch, all schools vary in their routines.
Any questions you have, ask the school or the Director or the Teacher.
If your son is not fluent in English and is shy or will not eat... then speak to the Teacher and you can give them a head's up and tell them. Most parents, like to tell the Teachers, about their child or about any concerns. So that, the Teacher is informed, about your child.
If you do not tell the Teacher/school anything about your child, then they will not know. So, many parents, commonly will speak to the Teacher. It is okay to do so. Parents in this country, very commonly speak up and ask questions.
Do not, be afraid to ask questions or to speak up, or to tell the school about any concerns regarding your child.
You mentioned that this is for "Preschool." Preschool is not like elementary school, with a "cafeteria" like you see in American movies. Preschools, are often smaller in campus size, or it is only 1 room, or a few rooms, and what not. And the Teachers, "teach" per the age of the children.
One thing you would WANT to do, and which I recommend, is to get from the school, any paperwork or memos about what their "rules" are... and what their "discipline" methods are. You need to know this, as a parent. Every school, handles & "disciplines" the children, differently. So see what your child's school, does.
And ask them, how would they handle.... a child who is "shy" or who does not know or understand English very well???? You need to ask them this. It is IMPORTANT.
And, how do they handle a child, that may not eat????
And also, does the school, have a "nap time" and what are the rules on that???
These things, are a part of Preschool.
And as the parent, you need to ask them this, and find out. And see if their answers to your questions, are, what you feel is appropriate.
Also ask the school, what the kids are taught there, and how they are taught. Some Preschools, are more "play" oriented. And some Preschools are more "academic." They all differ, in their approach... to the children and their school routines.