First big girl office job

Sorry if this is not the right place to post this. I just started my first big girl office job on Tuesday ( so it’s only been 2 days) and I feel like a disappointment already. I work for an investment company as the collections agent. The job requires me to collect rent as well as deal with everything money. So many folders and software things I have to learn and .. it’s very overwhelming. I like to consider myself a quick learner but this is crazy amount of information. They emphasized that mistakes are not tolerated but then gives me 1 week of training. I always offer to try the task being trained to me so I can remember better but once I ask if this is the right tab or I miss changing the zip/postal code for the building ( we have 2 different buildings with different zip/postal codes) .. they yell at me. Yes it’s a serious mistake but it’s also my second day. Any advice on how to work alone with high expectations once my coworker leaves me in a couple days? I write everything down but I don’t know if that will help enough . Thank you for reading