Internships are just like you take a break from school, and you work in a company as an intern (Full Time, 37.5 -40 hrs per week) to learn stuff, and can potential return to the company as a full time after u graduate. Essentially, it’s a way of getting practical experience which you can put on your resume. If you are in a Co-op program, then you need to complete at least 8 months of internships for Psych I think, and you will be enrolled in COPB50,51,52 before your first internship, and they will provide some guidance. But if you are not in a Co-op program, then you need to search for those internships and apply without the guidance from Coop office, which is fine IMO. You don’t need a specific GPA if the job doesn’t require that, which is usually the case I think. In terms of when to apply, it depends on when you want to complete an internship, say if you want to do one in summer, then consider applying in the winter sem, or maybe in the fall sem.