Unblocking Particular Website on MacBook Became Big Mess

This is a big mess please read with patience, thank you!

I blocked YouTube on my MacBook few months back but somehow I was able to access it without VPN (with VPN it was blocked), today I wanted to unblock it completely so I watched one video How to Fix Mac Not Loading Certain Website with the expectation that it would help me in unblocking YouTube, but it turned out to be a trouble for me, I explain how.

As per YouTuber's suggestion I tried the command networksetup -setv6off Wi-Fi but after this I am not even able to access the YouTube without VPN as well.

I tried to edit my hosts file by using the command sudo nano/etc/hosts but it shows command not found.

Please help me in unblocking YouTube completely.

I am attaching relevant screenshots.

Thanks for your time and help!