Apprentice level is harder than... that's a very funny one... Let me guess... you skip the prologue and went at it without traps...
Which map are you having trouble with? Strategies can vary greatly depending on the specific map you are playing so it is hard to give pointers without knowing which one you are playing.
@AngrySanta Are you playing on PS4 or PC? Did you play the first games OMD or OMD2?I haven't seen many people complain about Apprentice difficulty, maybe you are forgetting to use some important mechanic? Have you watched some video or someone else beat those levels, that should help a lot.