saving years of text messages

I'm sorry to ask such a basic question.: I have years long texts messages with my grandchildren and great grandchildren that I treasure on my iPhone, and can't imagine losing. I can scroll and scroll back but it doesnt bring me to the beginning. Is there a way for me to retreive all of our conversations? I have an iphone 10, and just recently got a Macbook Pro (Moterey). This Grandma would appreciate any tips :)