Hi Peony,
I used to be in charge of a baby room in a private day nursery and I think your worries and questions are perfectly normal.
Is your LO having any sort of 'visit' sessions to settle him/her in to nursery? In my nursery I would encourage parents, once they'd booked a place to come in for a visit with the child. This gave them a chance to experience how the baby room was run and a chance for me to ask them all I needed to know about their ds/dd's likes/dislikes, habits, comfort toys, medical conditions etc... I found parents would usually relax and then ask the 1000 questions they had been wanting to ask but were worried may seem obvious.
I would contact your nursery, and find out what their settling practice is is in the baby room, I would be very suprised if they just expect you to come in, leave him/her and go striaght off.
As far as what you can expect them to do with your LO during the day, I can only go by what we did in my baby room. We had a very babsic routine, nappy changes at 10, 1 and 4 (all babies nappies checked regularly throughout day and changed immedialtely if dirty/more than a bit damp- nursery only open 8.30-5.30) Lunch was usually 12 o'clock but this was incredibly flexible. Sleep times were whenever each baby needed one. Apart from that we would do all sorts of things,inc painting, drawing, dancing, singing, stories, outside play, etc.. we would rotate groups of toys too to keep them interesting.
Don't be afraid to ask what kind of things they do or about how much they actually play with the babies, you have a right to ask things like this.Try writing a list of questions, no matter how silly you think they might be, any decent nursery will be happy to answer them, they are used to new parents!
But above all, trust your instincts, no one knows your little one like you do!
Sorry if I waffled on, could yap in the olympics,
Hope to have been some help,
P&S