How does the TOR network and other P2Ps work?

Question

Tor

How does a new member of any decentralized network find other members if there is no central server that gives a list of member IPs, and iterating over all possible IPs is completely inefficient?
Is some kind of broadcast or UDP/TCP features used?
For the sake of interest, I want to make the simplest analogue of TOR. I can't figure out how everything is self-regulating.

Answer 1

https://en.m.wikipedia.org/wiki/Distributed_hash_table