GDPR - the General Data Protection Regulation - is law from May 25th and your staff will need to know how to comply with the new law.
It is recognised that different staff will need different levels of training. For example, an apprentice who is not completing children's records does not need as much knowledge about GDPR as a Room Leader or a Deputy Manager.
Staff training should cover the background to GDPR and how it relates to your staff members. For example, if a staff member is processing children's paperwork they will need to understand the importance of data security ... if a staff member takes documents off the premises to work on at home, they will need to learn more about keeping it secure and confidential.
A good starting point for staff training is this free video presentation from me, hosted by Childcare.co.uk.
I hope you find it useful. Sarah.