Finally Landed a Job, But I Have No Idea How to Do It

I graduated last year in CS, and recently landed a job in software development as an associate. The role was suppose to be for full time but they converted it to a temp role to see if I'd do well on the job since I lacked some practical experience.

Today, I got my first ticket to work on and realized, I have no idea what I'm doing. Lots of jargon, and concepts I'm not familar with. I tried asking for some help, but I'm finding trouble on how to ask it. On a high level I can figure out the process, but the implementation is what I'm struggling with since I have never used the libraries provided before and keep running into errors. I was given a file that has a similar structure for the needs of the ticket, but I'm struggling to apply it.

I never had an internship, and my experience is mostly in research and IT. Everything feels so different compared to school work.

I want to make this work, however, I totally understand if the company chooses not to convert me at the end of the contract.

To be honest, I expected a little more hand holding from the company to help ease me into work since it's an entry level job. But instead they threw me into a ticket after I did the mandatory trainings. Everyone has been nice so far, and I could ask them for help if I'm struggling. However, most people are busy working on different projects, I have a mentor but rarely see them around. Additionally, I feel like my problem is related to my inexperience rather than the codebase itself. I feel dumb asking how to implement something that is probably basic for their company when they gave me a structure file to base mine off from.

While I'm employed I want to learn as much as I can, so I have some "real job" experience for my resume. But I'll be honest here, I'm stuck in fear, and feel bad for them for hiring me when they could have gotten someone better.

My apologies for the mess of a story, but what's the best course of action to take for my situation? I'm worried if I tell my supervisor directly, I have no idea what I'm doing, she'll realize they messed up hiring me. I always thought entry level roles were more about learning, but it feels more like trial by fire. Thank you for reading about my situation.