Read the research paper about the Chord algorithm: https://pdos.csail.mit.edu/papers/chord:sigcomm01/chord_sigc..., then implement the algorithm on your own (paper contains pseudo code).

Or start here, generally read high level details about the algorithm: https://en.wikipedia.org/wiki/Chord_(peer-to-peer).

So cool to read this, it is how i started!

I second this advice. Chord is a very good place to start