Try to obtain and read copies of the following books. You may like to look for them at your local library:

‘How to say the right thing every time: communicating well with students, staff, parents and the public’, by R.D. Ramsey, published by Corwin Press
‘Crash course in managing people’, by B. Clegg and P. Birch, published by Kogan Page‘The confidence to be yourself’ by B. Roet, published by Piatkus