The easiest way for students to gain teaching experience is to serve as a Teaching Assistant for the PSY 100 course. This is a 1 credit commitment and responsibilities can include grading assignments, proctoring exams, and offering tutoring hours. Contact Dr. Alex O'Brien (firstname.lastname@example.org) if you're interested. The department recruits approximately 15 TA's every semester.
Individual professors may choose to take on a TA for more advanced courses, but these opportunities are less structured. If you would like to work with a specific professor, there's no harm in contacting them and expressing your interest.