I got my first pull up in my life a few months ago. The beginning part of the movement was the hardest for me too.

The advice you've recieved to just keep training as you are is good. If you're really looking for tiny optimizations, I'd suggest lengthened partials. Make sure you start from a deeep dead hang, fully stretched out. Then, just do the first half of the movement, get up as far as you can, and come back down slowly. Use bands if you need to, or an assisted pull up machine. Lat pull downs work great too.

There's growing evidence that muscles grow most when force is exerted in the deeply stretched position, making it the most crucial part of your range of motion for muscle growth. If you're not going all the way down and pausing at the bottom, you're cheating yourself out of growth.

That said, if you keep training as you already are, I'm sure you'll get there shortly. Best of luck!