Summary data report/chart

I want to have a Dashboard Chart or Report that sums and subtracts various parameters.
For example:

  • Net from the purchase invoices
  • VAT for the purchase invoices
  • Deductions or Loss form Payment Entry

I’ve been working with ERPNext for not a long period and I don’t understand how to reach the point.

Can Someone can help me? Thanks

Anybody can help me to understand how achieve this request?
Is necessary create e query report?
Let me know please. Thanks