Struggling with first job (Stock associate)

So I recently got a temporary job at Zara working in the back as a stock associate, I had my first shift and I'm just struggling soo much. I'm making so many mistakes and I'm just too slow. I have to scan items in a massive warehouse and load them to take to the shop floor all day. The problem is that I take too long trying to find the items and using the scanner effectively. I think I scanned about 3 items in half an hour and when my buddy trainer came back he told me off saying I'm going wayyy to slow as the normal expectation is to scan about 50 items in one hour. I just get confused with the code and numbers for each type of clothes and forget where everything is... I feel like I'm going to get fired from this position because although it's my first day... im just taking way too long to grasp things. I don't feel like I'm actually earning the money that I'm being paid... I'm just standing around and struggling without making any progress. Does anyone else who worked as a stock associate have any tips for me to get better faster? Thanks.

Speak up and explain the issue to your supervisor. Could the process be improved to make it easier to find items? Do you need to make notes and revise them when off-shift, to learn the system? Are there other people working the same job that you can ask for tips?

were you given any training?
if it's only your first shift so your still brand new and of course you're not going to be amazing as you're still learning.
just hang in there and hopefully you'll pick it up, you could also ask your manager for a bit more help

Yes I was given training and t's actually a really straight forward thing once I was shown what to do. It's just that im too slow and I feel like I'm not picking it up fast enough especially when my buddy trainer kept constantly telling me i have to go much faster. I spoke to my manager and she said its OK I'll get better with more practice, the most important thing was that she wants me to gain more knowledge about WHY they do this job and to learn more about the process and how important it is for a busy store like ZARA. That's all good and all but this is a PAID job contract not student work experience... And I need to actually make progress right?

Yes I was given training and t's actually a really straight forward thing once I was shown what to do. It's just that im too slow and I feel like I'm not picking it up fast enough especially when my buddy trainer kept constantly telling me i have to go much faster. I spoke to my manager and she said its OK I'll get better with more practice, the most important thing was that she wants me to gain more knowledge about WHY they do this job and to learn more about the process and how important it is for a busy store like ZARA. That's all good and all but this is a PAID job contract not student work experience... And I need to actually make progress right?

I was like that when I started my first job and honestly you’re probably just overwhelmed because it’s all new. I promise you’ll pick it up quickly. It took me a couple of weeks to get into the swing of things.
If your manager says it’s okay, then you’re probably fine. If there was a problem they’d just tell you because they don’t want to pay someone to do a bad job. Like I said, they wouldn’t have expected you to have been perfect on the first day.

Honestly try your best but don't stress and worry about the job. Just think what's the worst that can happen, they'll fire you. Even that isn't a bad thing you'll have gained some experience and you'll just as easily get another job. I know companies who have even hired ppl who broke the law.

I was terrible when I first started working in admin and made so many errors in my first role. Now I'm really good and I'm the strongest in our team of 10 people....it's just I no longer enjoy admin and I'm trying to get out....