What to do with the selection does not contain a main type error?

Question

Java

Vsm hello. I just started learning Java, and on the very first compilation in Eclipse I ran into a problem. I wrote the simplest code to display Hello world in the console, but nothing happens and gives an error: selection does not contain a main type.
I googled the kid, but nothing helped. Tell me what to do.

Answer 1

Everything is simple.
Buy a book on java.
Reading. You are studying.
How to write hello world will be on the first pages.