No, empty shelves should not be the norm. Were the children really "running around" because that sounds like they were aimlessly running around, vs. being interested in various areas of the room and focusing on them. In preschool, which is MA is for children 2 yrs, 9 months, you should see the following "interest areas" where the children can learn specific things with a few friends:
manipulatives (legos, puzzles, counting bears, counting cubes, sorting materials, etc.) for exploring math concepts
science center (large plastic magnifying glasses, various collections, perhaps plants growing, seeds for counting, sorting and classifying, or rocks, pinecones, etc. that they can explore and learn about. a scale might be here so they can weigh things and find out which things are heavier, lighter, etc. perhaps there are graphs posted about things like "which vegetables our class likes" or "who has green eyes, brown eyes, blue eyes"
dramatic play (often called housekeeping although I hate that because it could also be a doctor's office, restaurant, vet office, garage) - but usally there will be a stove, refrigerator, sink, small table and chairs, and pretend food, dishes, table cloths, telephone, pens and paper for taking orders, dolls, cribs, blankets, dress up shoes, hats, scarves, sometimes clothing.
language/writing center (pens, pencils, markers, paper of various sizes and shapes, stamps with letters and numbers - everything for children to begin doing their own "writing" and making their mark)
art area (where they will be encouraged to get messy and be artistic and creative) -
sensory table (playing with rice, flour, sand, water, or other textures)
library/cozy area (where there are books on shelves down low for children to choose and read/look at by themselves, with some pillows, or bean bag chairs or a small sofa or a quilt to sit on and get cozy with a friend or two as you read. puppets might be here, or they might be in another area of the classroom.
tables for lunch, art, play dough with low chairs that the children can get into/out of themselves
cubby for each child
bathrooms which toilets that are either low or with nice firm step stools to get onto the toilet. often you'll see that the bathrooms are used by both girls and boys at the same time - this is fine and great, they can see what the other 1/2 looks like, and is very natural for preschoolers - it's as children get older that they'll want their privacy.
and an area where they can have circle or morning meeting - large enough that all children can come together for stories, songs, finger plays, discussion, etc. this might be using the big block area for circle time, that often happens that you use one area for two uses.
cots or mats for nap time - you'll provide a pack and play sheet and a blanket at nap time.
now, there doesn't need to be 1000 books, 2 million manipulatives choices, but there should be shelves that have several boxes of manips, there should be 10 or 12 books on the book shelf (the teachers will have other books they read to the children that are kept up higher because preschoolers are incredidbly hard on books and will rip them accidently), there should be 4 or 5 sets of plates, cups, bowls and some pots and pans in dramatic play, etc. this way children don't need to fight over scarce resources nor sholud they be arguing over the 2 trucks in the room, they have a hard enough time sharing without having not enough equipment.
if you aren't happy with the center, then it's not a good program for your child, fram! Just because others go there doesn't make it fabulous.
And if your child isn't 2 yrs, 9 months then she's in the toddler/twos program and unless things have changed drastically, the ratio there is 2:9 - that is, 2 teachers, 9 children. In preschool (2.9 yrs to 5 years old) it's 1:10, 2:21 - so 2 teachers with 21 children. Yes, that's a lot of children, but it should still seem that theings are in fairly good control, that the children are busy, involved, and not careening around the room poking and kicking and dumping - that's the sign that they aren't in control of the children, that they don't have enough programming, curriculum development or materials, and I'd stay away. That they have a method to geting the children to leave circle, get their coats on, line up and go outside - instead of a mad dash of 21 children tearing for their cubbies, thrashing into coats, whining they can't zip, etc a teacher might be in the circle while the other teacher positions herself at the cubby area. And dismiss them with "if you're wearing a blue shirt, you may walk over and put your coat on." in a minute or so, "if you're wearing a yellow shirt, you may walk over and put your coat on" and so on.... this makes things more orderly and safe, and actually moves things faster. When most of the children are ready, start walking out the door and the last few children are helped into their coats and then follow the crowd. No need to have the class spend 10 minutes sweating in their coats and mittens and hats! Keep visiting, and do visit at 10am (ish) so you can see the morning progarmming in action - not at 8:30am at drop off, or at pickup times.