First day at burger king

First day at burger king So today was my first day at burger king and it went okay(drive through). One time I had a block towards the end of my shift so I couldn't say “welcome” so I said what do you need. The lady went crazy and demanded to talk to the manager. The manager then said its his first day. The lady then proceeded to give me a 5 minute lecture on how to treat customers. I don't stutter much but its cuz I'm good at hiding it. Do you guys recommend I stick to drive through?