How do I use a diva cup


So I'm 13 and I have a very heavy flow, my mom and I have been trying to find what I can use on my periods, and for now I wear a ( super tampon and a night time pad at the same time I still bleed through every time) I'm going to the doters sometime i think so please don't tell me to do that I just need help learning to use a Diva cup, I'm really concerned and I'm really needing help, im going in the shower and squatting down and reading about this on instructions help me please older girls who've down this before