The experience of working in a firm with trained professionals in my field. It was easy to talk to everyone there, and ask for help when I needed it. I loved all of the office-wide training sessions we had.
What I wish was different
I wish the pandemic hadn't hit and we didn't have to go remote.
Advice
Know that you will be a drafter for awhile before you get to design anything much: something I have found to be typical of most design firms. However, design work will eventually come.