Watering help

I have two olive trees, two grapevines, two blueberry bushes in containers, and a pomegranate tree. They are all in my first year having them, so I don’t want to hurt them, but how do I know if I am watering them correctly? I am used to veggies where I know how often and how much to water them, but how do I know that with trees? I understand to check the roots, but I am not sure how to do that without hurting the roots. Thank you in advance!