I currently work at staples. I do talk to people, tell them where things are and any other assistance they may need. Although I am not stutter or anxiety free, it helps when people approach you and you can give easy answers and if you're awkward or whatever, who cares, it's just some customer in staples, not a social peer group or a hot girl or whatever. Nevertheless, go for available jobs, you cant be too picky in a high school job. I should also add that during high school, I worked at a doggie daycare. This was nice bceause I rarely had to interact with people, only when they picked up or dropped off their dog, so it was minimal. If you wanna go this route, look for jobs involving animals or even stocking shelves at a grocery store. There are options, but don't limit yourself too much