Basic terminal commands not working such as /sudo,/ping,/ls

Question

Here's the terminal output

cat@cat-B460M-DS3H-AC-Y1:~$ /ping
bash: /ping: No such file or directory

cat@cat-B460M-DS3H-AC-Y1:~$ /hep
bash: /hep: No such file or directory

cat@cat-B460M-DS3H-AC-Y1:~$ /help
bash: /help: No such file or directory

cat@cat-B460M-DS3H-AC-Y1:~$ /sudo
bash: /sudo: No such file or directory

Answer 1

Enter them without the leading "/". You're on the command line, not the console of your favourite game ;-)

Answer 2

Remove "/" from commands, You entering wrong commands.

Original commands are :

sudo
ping 
ls