Tobster911
Whether or not you can teach with a PPL is a legal question. Since I am not very familiar with the way things get done across the pond I can't answer that question.
What I can comment on as a long time instructor including completing many instructor ratings, is that the average fresh from the flight test CPL does, in general, not have a high enough level of flying skill to properly demonstrate any manoever and the first part of the course is invariably used to raise the students flying skills to an acceptable level.
I have never flown with a low hour PPL that was any near the skill level required to instruct. If you do intend to progress towards a flight instructor rating I would suggest it would be prudent to budget for a significant amount of addition dual to raise your skills to the necessary level.