I would think said person is just shy and reserved and just trying to find something to do instead of gossip.
You’re doing your job and that’s what you’re supposed to do if no one will train you further.

If I were your co worker I would try to talk to you and get to know you. Don’t listen to these negative Nancy’s.

As a supervisor if I noticed that a new person was more reserved I’d make extra effort to talk to them and make them feel welcomed to the store. I may even reach out asking about how you’re feeling on bar/about the store to make sure everything’s going okay. It’s totally okay to be more quiet or reserved, If you would like more advice and feel comfortable with your sm I would recommend talking to them.

Woof, that feeling when you know they're talking about you is literally the worst. Even if high school I didn't get that kind of treatment, but at Starbucks? They make smalltalk around me and stop dead silent when I try to be friendly and join in the conversation, which is a dead end as far as I'm concerned. Not sure what I did but I'm certainly feeling the burn.

Hang in there. If you can switch to a different time of day, things might be different. I worked a store where the closers were super cliquey and if you didn't complain with them about how terrible the manager was, they would start giving you all the crappy tasks and "playfully" mocking you. But the openers at that store were great and welcoming. So I just told my SM that I was having trouble with the negativity on the closing shifts and she switched me out to mornings moving forward. Loved that store.

And if your SM/shifts won't help, there are always other stores.

you’re new, I’d EXPECT you to be a little hesitant/shy. i’ve always tried to get to know our green beans & be real patient because this job takes a while to pick up. the only time i’ve ever stopped trying to get to know a new hire was because she seemed like she disliked me (didn’t initiate conversation but she would with other people on our shift, would pointedly ignore my attempts of conversation/gives one word answers) but i’ve always loved getting to know everyone and teach our green beans. it’s really cool getting to see y’all get the hang of stuff and grow into a skilled barista!

I had a somewhat similar experience as a new hire. I was enthusiastic and attempted jokes every now and then but apparently wasn't talkative enough for one of my coworkers. He would tease me all the time about how I need to "open up" and "talk more" while laughing at me. It definitely didn't feel anything but meanspirited and embarrassing. I think some people are just built like that. Being quiet isn't a bad thing. Do your thing.

Yup. That is Starbucks!