After writing "cd udemy- course". It appears that "ls" is not recognized as a command

[ezepale]

file:///C:/Users/MI%20PC/Pictures/help.png

[eddiemonge]

ls does not work on windows. You want dir instead

[psyycker]

Unless using powershell, in that case, ls is a valid command

[eddiemonge]

or using WSL2 like I highly recommed