@cristine , in this case your results.toString() is correct because you used the .count() feature.
This returns a number and not an array of items. Therefore it is NOT possible to use .items.length in your case.
Your code, where you count the number of rows(records) that match the ‘firstName’, looks good to me, but of course, I wasn’t able to test and run it. You can actually confirm if you get the correct number back by using:
console.log("The value of count is: "+results.toString());
Insert this after the .then() line.
From what I can tell, it looks like you have the count, you just don’t know how to insert it into the repeater. This is why I need a bit more information.