Google Sheets built-in "On form submit" trigger

New challenge. Sheet has many records, but my app will let the user check a box on a particular record for a particular column. Eg, Task is now complete, check the box. After user checks the box, I want to pull data from that row and send emails and SMS based on field values in the row. I looked at filters and loops, but feel like I am missing something conceptually. As always, guidance appreciated.