So I want to ask for a different dressing on my burger.
Didn't you already ask for different dressing?
I've asked twice already and the only reaction I got was a blank stare.
If you are eating out, it is good to ask for the food to be how you want it. The restaurant is providing a service and should be able to fulfill our request.
It's fine, they are just to young.
Respectfully ask the manager for what you want. The waiter might be having personal issues or just having a bad day.