Asimov started writting The Foundation in his 20s and started to be published by chapters in a magazine in the early 50s. Its a trilogy, then in the 80s he wrote 2 precuels and 2 sequels. The books are kinda short.

Being prized with the "Best all time Sci Fi" it was never  made to TV for a reason. Then a few years ago Apple did a horrendous ultra woke tried, that I'm so glad Asimov was not in this world to see it. 

THE POINT - You got your the book you are looking for, don't look anymore.