Agree with PP who said that the dress codes in schools vary significantly.
I have 3 work styles, dependent upon the season.
Winter: jersey / ponte dresses with cardigans, opaques, boots
Spring / autumn: 7/8 trousers, shirts / blouses, pretty floral or print tops etc. Flat shoes (not quite ballet pumps because they hurt but something along those lines)
Absolute height of summer when it's 30 degrees and you're still trying to teach despite losing the will to live: button through shirt dresses.
In shopping for work wear, you might also want to think about a coat with a hood because it's not only playground duty, it's the staggered finishes meaning a lot more standing round dismissing children at the end of the day than there used to be.
Also, check out your school's expectation for staff PE wear. In every school I've worked in, the expectation has been that teachers wear PE kit all day on PE days. The yes/no for this can vary a bit from school to school - a friend was subject to a 'quiet word' in her school about tight Lycra gym leggings, whereas these are accepted in my school.