How to sound 'natural' to my grandparents instead of like a textbook?

My family is from rural Galicia, and I'm trying to learn the language to connect with them, but I find that standard Galician resources don't really capture the natural cadence or specific idioms my grandmother uses. I feel like when I speak, it sounds robotic. Is there any way to adjust my learning to favor more natural, informal Galician without getting overwhelmed by dialectal differences?