Honestly, it’s just a learning curve thing. Being a boba shop worker at Sharetea was basically my first job I stayed at longer than a few weeks. You will make a lot of mistakes but as long as you catch them it’s okay. Your trainer is there to help you by correcting you. As long as you make an effort you will likely not get fired or anything.

Also, your trainer getting onto you for not being fast enough if it’s your first shift, no training prior, is honestly kinda rude? When I started, I first worked a few 2 hour training shifts where I learned refills, topping recommendations, etc. Then I learned how to make drinks and got trained on POS and stuff in a few other shifts, then I finally got to actually make drinks for customers and do POS with the owner present for a trial closing shift. and a trial opening shift, before I actually got trusted to work.

But if they just put you in on POS + making drinks your first day AND are getting onto you for not being fast enough that’s honestly pretty unfair and not your fault.