Midnight Commander is quite easy to use. It is what file managers used to look like back in the days of Windows 3.1 You may be too young to remember
On starting you will see two panes, one on the left pane, one on the right. To start with both panes will show your home directory.
The 'Tab' key will switch the focus between left and right panes. This allows you to work in two folders at once.
Scroll down the pane using the down arrow on your keyboard until you find a folder called 'Desktop' clicking on the folder will cause you to enter the folder.
(Clicking on the '.' at the top of a folder listing causes you to exit the folder.)
Now scrolldown with the down arrow to the file you want to delete and delete it using the F8 key
at the bottom of the screen you will see a list of frequently used commands and their function keys.
To exit Midnight Commander use F10
F1 gives a help screen Esc will exit help.