I unlocked chocobo training at lvl 30 on archer class but I prefer magic classes so I'm busy leveling CNJ, ACN and THM. All below 20. Can I train chocobo too or do I need to wait until they are also level 30?

Either way, I can't remember how to 'get choco out' to fight? I unlocked it last year and there's so much I've forgotten oops. I know I need 'greens' to feed it and I have those in inventory. I tried googling but didn't find my answers.

Thanks