Answer: For the first one, I'm not entirely sure but I believe it's the, "Sincerely. Thanks," part. When you say "Sincerely" you usually put a comma after it and your name.
For the 2nd one, "Serves" should be "Serve." For the 3rd one, the quotation marks should only be around the words "Best fries" and the "F" in fries should be lower case.
Explanation: I really hope this helped. If I'm wrong, I apologize.