There are lots of places you can go for support if you have a concern. The important thing is that, even if you are unsure, you talk to someone and get advice:

Is there immediate danger or injury?
If yes – Contact the emergency services.

Report or seek advice on a sports related concern:

If the sport or activity has a National Governing Body, refer to their safeguarding procedures about who to report the concern to. See here for NGB contacts:

If there is no NGB or you cannot contact them, you can seek support from a number of sources:

Child Protection in Sport Unit (NSPCC):
Active Essex: 03330 137827
Essex Social Care: 08456 037627

Report or seek advice on a non-sports related concern:
Contact Essex Social Care: 08456 037627

Essex safeguarding Children Board: 0345 603 7627