Below are links to suggested demonstrations for Newton's First Law.
Links:
[1] https://demoweb.physics.ucla.edu/node/150
[2] https://demoweb.physics.ucla.edu/node/100
[3] https://demoweb.physics.ucla.edu/node/151
[4] https://demoweb.physics.ucla.edu/node/102
[5] https://demoweb.physics.ucla.edu/node/101
[6] https://demoweb.physics.ucla.edu/node/99
[7] https://demoweb.physics.ucla.edu/node/79