Google Sheets – IF OR Script

First, the error: shs is an array, since you populate it with ss.getSheets(), so it doesn't have a method getActiveCell(). However, the elements of the array has that method.

You are also referencing a variable sheet, which you haven't defined anywhere.

Currently, your code is more suitable for going through a single sheet, you need to iterate through the shs array to have it operate on all sheets.

The following function will go through all cells in all sheets:

function onEdit(event){  
  var ss = SpreadsheetApp.getActiveSpreadsheet();
  var shs = ss.getSheets(), num = shs.length;
  var sheetName = [] 

  for (var sheetIdx = 0; sheetIdx < shs.length; sheetIdx++) {
      var sheet = shs[sheetIdx];

      for(var i = 1; i<num; i++) {
      ...
   }
}

But you wanted to skip the first sheet, so let's start with element 1 in the array (since the array is 0-based, element 1 is the second sheet):

function onEdit(event){  
  var ss = SpreadsheetApp.getActiveSpreadsheet();
  var shs = ss.getSheets(), num = shs.length;
  var sheetName = [] 

  for (var sheetIdx = 1; sheetIdx < shs.length; sheetIdx++) {
      var sheet = shs[sheetIdx];

      for(var i = 1; i<num; i++) {
        var editedCell = shs.getActiveCell();
        var columnToSortBy = 1;
        var tableRange = "A2:G99"; // What to sort.

        if(editedCell.getColumn() == columnToSortBy){   
          var range = sheet.getRange(tableRange);
          range.sort( { column : columnToSortBy, ascending: false });
        }
      }

   }
}

As for your comment, your code

function onEdit(event) {
    var ss = SpreadsheetApp.getActiveSpreadsheet();
    for (var n in ss.getSheets()) {
        var sheet = ss.getSheets()[n];
        var name = sheet.getName();
        if (name == 'Dashboard') 
           return;
        var editedCell = ss.getActiveCell();
        var columnToSortBy = 1;
        var tableRange = "A2:G99";
        if (editedCell.getColumn() == columnToSortBy) {
            var range = sheet.getRange(tableRange);
            range.sort({column: columnToSortBy, ascending: false});
        }
    }
}

could work, if you replace return with continue. You don't want return, it ends the script. continue skips to the next element in the for loop.

You can use MATCH to return the row number. For example if you're looking for the word "Help" in Column H, and it's on row 14:

=MATCH("Help",H:H,0)

will return 14.