whenever i try to lean anyones key techs, i press x at the right time but the player never actually learns the skill, it does the noise when u fail to learn a tech
ive looked at a fair few guides but none of them say anything
anyone know whats up??

It's the timing. "Techcopy" appears during the whole duration of the technique, but you need to press X when it's actually being performed. It's usually half way through, but for a technique like Sphere Shot it's near the very end.

Hi!

There's a really good blitzball guide here (Thread 5052) that should be able to help you out a lot. You can ask blitzball related questions there too. :)