FYI - Being on set / in a production is NOT the place to expect people to teach you. It's a place you can learn from.
1.) Preparing to go in to the production. Prep work is very important before you show up. I learn each time a better way for me to prepare before I show up.
I like to make lists for myself to review. I also add notes on what I've done and learned from this. I do this primarily in my Google Docs because I can highlight things to catch my eye.
2.) Who I want to work with again. I have had some not-so-good experiences. You will too.
I make connections and keep up with those professional relationships with the people I want to work with again.
I can't always pick who I don't want to work with again because I'm not the producer. I don't have hiring and firing powers or that kind of influence. So instead I try to make notes to myself of my experience with folks I prefer to not work with again. That way those notes may help me navigate my working relationship with them better.
3.) What is everyone's job. You really need to learn what other people's jobs are and how they connect to yours. There are people behind the position. Make a conscious effort to show them some kindness and humanity. You never know who they know or what else they do in this industry.
4.) What else can I see myself doing besides act? Going back to point #3 - if you ask people, you will find out they may do more than one thing. Only one person can fit in a role/job. I've met Actors on sets and productions who are working in other roles. It's a great way to still be a part of the industry, but use your skills in a different way.
If someone is willing to let you ask questions or shadow them a little, that's great! However, remember people are there to work, and not everyone is a teacher. Don't take it personally if someone says no.