Whether you're a student or a member of staff the process you will need to use is dependent on who the person is that you're reporting.
If you want to make a formal report about a staff members conduct you can start by making an advisor request through Report + Support, or contacting your HR Business Partner directly.
If you want to make a formal report about a student's conduct you can start by making an advisor request through Report + Support or contacting the student casework team.
The below guides offer more detailed information about the formal reporting process should you wish to find out more before making a report.