In the first instance you should always check with your lecturer or subject coordinator to find out what content and layout are required for the report you have to complete as an assessment task. The information may be included in your Subject Outline, or in your study materials.
In the absence of any specific guidelines, the following information about report formats may be useful.

A numbering system – especially for longer reports – is normally used to quickly indicate sections and levels within an report. Single numerals (1, 2, 3…) are used for the main headings; an additional numeral (1.1, 1.2, 1.3…) for second level of headings; and two additional numerals (1.1.1, 1.1.2,…) for any third level headings.
A report structure would look something like the following:
