Diva cups

So I'm thinking about trying out diva cups but I'm a little confused. How do you know when it's full and are leaks common? And also do you change it to a different one when the one you're using is full? Or do you use the same one after you've poured the blood out? And if so, do you have to like walk out the bathroom stall and clean it in the sink? 😂 Iol please don't judge me on my ignorance. I've never even heard about them til recently but I heard they're awesome