It will come to you , dont panic , just have to imagine every day is a school day
I've been selling for best part or 50 yrs Salt and its always fun in my head , Customers change but their questions and expectations don't , Just learn to tell the truth and be firm , Don't let them rip your heart out , because they will have a go , no morals in the buying public , most rude set of people on earth , but you will learn the retorts that shoot them down ,
I do actually get off on dealing with the public though , one big competition and I don't lose
Stick at it you will be fine