EMHP - Purely focused on school and colleges to increase social mobility and access through psychological support for behaviour, low mood, sleep etc. This is quite a new which is why there isn't much information on it. No professional experience is required to apply to the one year training course.
CWPs - Focused on low-intensity evidence based treatments for things such as anxiety, autism, behavioural difficulties etc. Requires one year worth of training (often based in schools, but not exclusively).
Have you considered the Child Psychotherapist route (as you mentioned wanting to work in CAMHS)?
Hope the above helps in some way?!