There is a red dot comes on my iphone 8 on right hand cornor i never noticed it before what is it?

Status icons and symbols on your iPhone

https://support.apple.com/en-us/HT207354

If you see orange or green indicators in the status bar 

With iOS 14, you might see an orange or green indicator in the status bar on your iPhone. These indicators appear when the microphone and/or camera are being used by an app.

An orange indicator  means the microphone is being used by an app on your iPhone.

A green indicator  means either the camera or the camera and the microphone are being used by an app on your iPhone.

Nisahooker wrote:

O is it something i turned on by mistake? Or is it possible that my phone is haked?

Did you read the posts above? They explain exactly what it is. It is a new feature added in iOS 14. You can't turn it on or off. Your phone has not been hacked. It means the microphone on your phone is in use. That is all.

No, it is a new security feature of iOS 14. It is meant to alert you that the microphone is being used. While this seems silly to display when using the phone (which has to use the microphone), it will also alert you if one of the other million or so apps available might access your microphone.

See: About the orange and green indicators in your iPhone status bar - Apple Support