Quickbooks Online payroll support and accounting advice needed

I need someone to help me set up the first Payroll run. I have input most of the basic information on Quickbooks, need to make sure things are set up correctly to process the first payroll (one lump sum salary payment for tax year 17/18), set up monthly ongoing payroll. Ensure NIC is processed correctly. I do not have a P45. Have requested payroll service from HMRC.

Do you have experience of setting up Quickbooks Payroll?
Do you have knowledge of the UK payroll system, as it applies to contractors / Ltd companies
Are you able to provide advice on optimal salary amount, NIC contribution and state pension?