Each education tier consist of two buildings, one that can only be in the capital city, and another that can be in all cities. The capital city can therefore potentially get two buildings per education tier. The one that can only be in the capital city does not have any tech requirement so you can all of them in the prehistoric era. Their only effect are to give longer anarchy time on civic change for positive education and shorter anarchy time for negative education. This penalty/bonus is not significant enough to care much about in the early game.