This video briefly shows how to setup and use the NanoVNA to sweep an antenna system (antenna, transmission line, transmatch, etc.) to measure its VSWR, Reflection Coefficient, etc., and then shows how you can use it to monitor the tuning behavior as you make adjustments. The basic steps include:
Setting the traces that you want to display (SWR, Smith, S11)
Setting the frequency range
Running a Calibration
Making the sweep
Using Markers
Please see my previous videos on the VNA, Smith Chart, Transmission Lines, Terminations, etc. for more background.
More on VNA calibration here:    • #313: Why a VNA needs to be calibrate...