How can I find my lost iPhone?

Hello Sir ,

I really do not know what to do. I want a solution in a quick way. I waited a long time to be able to return the Apple account, but after all this waiting, if I reap any fruits, I used find my device and it did not give any result. I am really shocked when I bought the latest Apple phone that has more What do I do to find my phone again?

[Edited by Moderator]