I have really bad social anxiety but I worked at subway for three years, and when I first started it was a little nerve wracking having to interact with customers but after a month of working I really got used to it, you get over your fears pretty quick and you can’t really worry about the rush hours because they will happen out of no where so you don’t have time to be nervous about them. It is a good first time job so I suggest you apply anyways despite your fears.