Ethical hacking from scratch

Hello,
I am having problem with nmap, when the nma is completed all ports are filtered and i get no information.
Can anyone please help me with this one?
Thank you

Hey and welcome andros7,

You know Nathan has a blog?
He made a real nice cheat sheet.

https://www.stationx.net/nmap-cheat-sheet/

if you still don’t get a result with 1 of the commands. Then there is probably something else going on. (network or something)