How to tell a script which row to start output-CodePudding

I am using a script to output the date and time that a row was last updated on a Google Sheet. It seems to work just fine, but I want it to only output beginning at the second row, since my first row is a header row full of labels for the columns. I can't seem to figure it out.

The script is from here: https://www.wikihow.com/Google-Sheets-How-to-Insert-Time-in-Cell-Automatically#Script-Editor

This is how it looks in my Apps Script:

/** @OnlyCurrentDoc */
function onEdit(e){
const sh = e.source.getActiveSheet();
sh.getRange ('A'   e.range.rowStart)
.setValue (new Date())
.setNumberFormat ('MM/dd/yyyy HH:MMam/pm');
}

I think I need to define rowStart, but I'm not sure how to do that and search engines haven't pulled up answers I understand.

I tried appending rowStart(2) and rowStart > 0 in place of the original rowStart, which produced errors and made the whole script stop working. I also tried the below with the same response.

rowStart( 
   value : 2
) : 2;

From here: https://help.grapecity.com/spread/SpreadJSWeb/JavascriptLibrary~GcSpread.Sheets.PrintInfo~rowStart.html

I am new to Google Apps Script (and any scripting), though a longtime Excel and Sheets user. So please explain it to me like I am five.