There are formal and informal relationships you can have with your professor; you seem to feel the need for an informal mentoring relationship. That means that you need to get to know the professor and vice versa.

Every professor holds office hours (it's an obligation that comes with teaching). Make an appointment, be on time, meet with the professor, and talk with her/him about things that interest and concern you. It helps if you are up-to-date on events in your chosen field and have been doing some research on your own--but that's not mandatory. You can also ask for help.

Interaction with bright, interested, and thoughtful students is a primary reason your professor is teaching a class. The professor is not going to be worried about whether you have a side-project or what sort of grades you have gotten on your homework assignments. She/he will be interested in whether you have been thinking about the field and whether you have interesting ideas.

Office hours are often the most exciting time of a professor's day (35+ years of experience).