I had Turbo C as a young teenager, but really learned C at the csh prompt of a terminal connected to a giant DG/UX computer in my first summer job.

I actually still don't know BASIC.

Unix/Linux historically gave gave you a shell prompt (allowing you to type in shell programs) after login and a C compiler in the box. Modern Ubuntu or macOS technically still have terminal apps and shell prompts, but usually boot into a desktop GUI.