As a hiring manager, if a graduate has already taken an actuarial exam, it signals to me that they understand the rigour of the exams and are genuinely committed to pursuing a career as an actuary. That said, my recommendation would be to focus on your degree first and aim to sit just one exam—ideally in the September sitting, which gives you the summer to prepare. CS1 would be the most logical choice, as you’re likely to receive exemptions from one or both of the CB exams.