First time user. Help!!

Okay, I received my cup and today i started my period. I’m only 16 and I’ve never given birth so I used a level 1 cup. I do have a heavy flow. So when I put the cup in I made sure it was fully open, however nothing actually went in the cup! It all came out around it. What am I doing wrong? Help!!!

Edit: I ended up using a tampon because it leaked or whatever while I was at school. I reinserted it after cleaning it when I got home and I’ve just been doing homework and so far it hasn’t leaked? I’m still a little hesitant on how well I’m inserting it.