エラー内容は下記のとおりです

[root@localhost java_lessons]# javac Myapp.java
Myapp.java:1: error: class MyApp is public, should be declared in a file named MyApp.java
public class MyApp {
       ^
1 error

バージョン情報です

[root@localhost java_lessons]# java -version
openjdk version "1.8.0_252"
OpenJDK Runtime Environment (build 1.8.0_252-b09)
OpenJDK 64-Bit Server VM (build 25.252-b09, mixed mode)
[root@localhost java_lessons]# javac -version
javac 1.8.0_252