Speaking fluency help

Any elementary English teachers here? I need some advise (honestly it can be from any native speaker). How do I become a pro in pronouncing any words (new never heard of words) correctly? What is the foundation that i need? I noticed my child who is in first grade is already doing fantastic in correctly pronouncing words that she never heard before. That made me think there is something that is taught in schools here for little children as a core foundation that I need to learn, but I don’t note what that is. I don’t want to go learn ”crash” courses, I want to get my basics right so I can speak fluently and pronounce ANY word correctly. Please help!!🙏🏻 There was once I prounced the word Cannes as “CAY-nes” until someone corrected me in a group that it is “CAANNS” I was so embarrassed. I don’t ever want to be in that situation again. Please advise