Why should I consider choosing the right shape of a menstrual cup?

What are FB groups? How does the process work when it comes to being funded for your cups?

Not that I’ve worn a cup before. But I’ve been doing a lot of research on them on different websites, looked up on the different brands on different websites and read testimonials, watched youtube videos of different brands and the testimonials from women who tried or use different brands. Also took notes from a few youtube videos. So I want to pick the right characteristics of a cup before I buy it.