How does one node connect to other nodes I am wondering how does one client connect to whole blockchain system if there is no centralized node which connecting other nodes together?

So for example if I want to create my own decentralized network how should my client now where to connect?
There is no centralised server required.

1.
If you start a node the first time, it will try to load a bunch of other nodes IPs via the build in list of available DNS seeds (there are ~5 seeds available).

2.
If those DNS seeds are not available, the Bitcoin-Core client uses its fallback IP list (a regularly updated list of IPs)

3.
Once a node could connect to one of those IPs (retrieved via DNS seeder or static list) it will ask for more IPs from known nodes (p2p address relay)