What was your first day at your first dev job like?

Mine was in a startup as an intern/junior developer and after I received the computer I would be using in the office and installed VSCode I had to talk with the previous developer that was leaving to another job, so that he could explain to me how the code worked and how to setup everything (Homestead and stuff)
After that I spent a few weeks studying the code and only after that I was asked to make some css changes and only after that some real changes to the code

I'm currently on my first dev job (before this I was an IT consultant).
It's weird to say this, but since I'm in a remote position, in my first day I really had no tasks at all, except reading a few mails. My employer wanted me to use a specific laptop for the job; under a VPN and such. Had to wait a week before getting it delivered to me, then another week to get the whole environment setup; VSCode, Node.JS, Office apps, company/Slack/cloud storage credentials, etc...
Even weirder, I got in as an "Angular Developer", but right now I feel like an IT support staff member. The time will come when my dev tasks are assigned, but right now I'm taking the chance to learn a lot of new stuff on Linux and what else.

I guess you're never too old to become a Junior Dev. I've started my current position as a Ruby on Rails developer six months ago, when I was just shy of 32 years old.

I've studied Computer Science but for the following ten years I've worked in the video industry. After closing that chapter of my life, I got back in tech as a Linux Sysadmin (thanks to the plenty of Linux stuff present in the digital cinema world) but I knew I wanted to get a position as a developer, which I actually managed to get thanks to a remote first company that's making me grow as a Rails dev and all around as a human being.

The first day was the usual "get all the credentials needed and read the onboarding documentation" but it was also the moment I understood it was very real when I introduced myself to the client in the standup.

At the start there was a lot of impostor syndrome, and reviewing code written by people way more experienced than me felt daunting and I was constantly on the edge. Now that feeling is waning thanks to the supportive team and the small wins, but it's always lingering.

First day for both dev jobs I've had so far were pretty mundane, but I was still nervous. They typically involved just getting everything set up, maybe studying some code and meeting people, and very little actual programming. I assume as I grow in my career the expectations for me to hit the ground running will become greater and greater, but since I've basically only had junior-level positions so far, there was plenty of time to get used to the environment and code.

It is illegal for me to get a job. :)