New to programming; Issue with CLASSPATH (i belive) when running java file from windows CMD


As the title says, I am new to programming and recently I decided to learn Java. I have been going through Mosh’s course for java, and in the beginning of part 1 he shows how can you compile and run a java code from command prompt. I tried to replicate the exercise on my machine several time in different ways but I keep getting this error:

I have read about CLASSPATH and thought that the issue might be that I need to create a new CLASSPATH from advanced system setting, which I did but the issue remain.

Any help would be appreciated and thank you in advance