Mine was BASIC - specifically, BASIC on an Apple IIGS my dad bought for us in 1987 or 88 (I forget which, I was young).
I learned it from my middle school math textbooks, which included entire units on how to code in BASIC. My math teacher always skipped them, which I hated, because I was much better at coding than I was at calculating.
Cool, another Liberty BASIC practitioner! What do you code in these days?
When I was in elementary school, I learned Scratch using a book from the library. It was nice to learn the fundamentals, but I would consider Python my first real programming language. (Real meaning something with syntax.)
Today, I hate Python and only use Rust and JavaScript/TypeScript.