Only a slight problem. You can CD to the correct directory and save the file there, also.
When you get to the "Temp" directory:
Hello.java
Your system is likely to be slightly different. Experiment with different choices until you are able to create a text file that contains the sample Java program.
Fussy, bothersome, irksome, irritating details. Yes, I know... Some people actually like this stuff. But if you can drive a car you can do this. It might take some practice.
So, finally your Java program source file is saved. What must you do to run it?