In order for you to get the Stimulus money for 2019 you would need to file a 2019 return. If you are not required to file a normal 2019 return, then yes you would use the Non-Filers form on the IRS website.
The IRS will use your parents 2018 return for information about their stimulus if they do not file a 2019 return, if they also are not required to file a normal 2019 return, then they can also file a Non-Filers form for themselves.
