If anyone knows any site that buys selling Bitcoin worldwide and doesn't have any verification and most important trustworthy..?
Any site that doesn't want to know who you are, will get abused by scammers.
That means legit sites will want to know who you are, and if they don't ask that, you're probably better off not trusting them.
He also wants a good rate for bitcoin, you might need to compare with these exchanges. There are exchanges with fiat to cryptocurrency trade now but such trade can be limited without KYC.