Fingering myself

I tried to finger myself for the first time but still didn’t work out. I don’t know where to insert my fingers. I looked at a diagram and I’m still struggling. Last time I opened my lips and put my finger closest to where the diagram shown but it’s like it wasn’t going in...was I at the wrong spot, I’m confused. Is the hole small? I was turned on enough and pretty wet so I don’t know what the problem was...