For us with a single child some things are easier at pre-school/nursery like playing nicely, taking turns, talking to adults independently, asking adults for help.
Others are - for me - things I as a parent are responsible for like table manners, clothing issues, food container opening. We obvioulsy also played board games (good for taking turns practice), listening to stories and waiting nicely if mummy/daddy are busy, doing things independent like taking bowl and cup to the sink, tidying toys.
Toilet habits is always a joined effort. Our nursery started the term before the "big kids" go to school with letting them do their business without constant checking and reminding (they send a note before, preparing parents for more knickers needed). I also found that DD would do it a lot more indepent at nursery than at home. Cheeky one.
With 30 idential or nearly identical items like jumper/cardigans, book bags, water bottles, shoes it is vital they can recognise their name. Big colourful sticker are good. We iron in labels at the neck, easier to spot than writing it on the label.
If they have a decent knowledge of numbers, letters, shapes, colours it is a good bonus. I don't mean reading/writing/doing sums but recognising them and maybe counting.