This girl who is a plate for now.

She doesn't cum via penetration or with fingers.

So it has to be mouth. I have never done this before.

I tried, it she moaning and at one point her legs were shaking. But no orgasm. My toungue got tired so I just gave up

Going forward 1. What area am I aiming for? The clit? Or inside the top of the vagina 2. How do I make my toungue stronger? 3. What sort of motion should I use with my toungue? 4. Any other general tips?

I don't know why but I get fixated on little things like this, and it sort of bugs me until I can overcome it.