Beginner Question: How Do I Crop a PNG Inside a Circle in Illustrator?

Guys, I’m going to ask a somewhat silly question, but I really need to get this straight once and for all. I’m still learning Illustrator, and although I’ve managed to create clipping masks a few times, I always end up scratching my head over it. It’s incredible how different and unintuitive this tool is compared to Photoshop. I’d like to understand the simplest way to cut out this empty area and keep only the part inside the circle. Just to clarify, this isn’t a shape — it’s a PNG.