Lead first of children into English class (6)
I believe the answer is:
Here is my best explanation:
'lead' is the definition.
(I've seen this before)
'first of children into english class' is the wordplay.
'first of' says to take the initial letters.
'into' is an insertion indicator.
'english' becomes 'e' (abbreviation).
'class' becomes 'sort' ('sort' can be a synonym of 'class').
The first letter of 'children' is 'c'.
'c' inserted inside 'esort' is 'ESCORT'.
(Other definitions for escort that I've seen before include "Entourage", "Person accompanying another", "Armed guards", "Social companion or military guard", "Armed guard", "One who accompanies, for protection or as an honour", "bodyguard", "Act as companion, attend", "Companion, perhaps for protection" and "Custodian".)