Sorry I didn't see your question earlier! You are making a great choice to sub while in school. As you have assignments in your class, see how you might integrate them into your teaching. Talk with your principal about what you are learning and ask lots of questions. Be curious and interested in everything you do. As a sub, follow the lesson plans left for you and smile. Students may want to try you since you are temporary, but smile, be patient and have fun. If you enjoy your time while subbing, the students, staff and principal will notice. Volunteer for lunch duty or other "jobs" that others might not want to do. Show your commitment to the school and your students. Stay positive! That energy will show and transfer into all that you do.
I found this article that might be helpful: https://swingeducation.com/resources/24-tips-to-engage-and-delight-your-sub-class-from-the-moment-you-walk-in-the-door/
Read it at your leisure and much luck and success! I'm an elementary teacher who was a parapro/assistant during college. I loved it!!