my macbook shows wrong location.

It’s never coorect. There can easily be a difference of more then 100 miles

Are you connecting to the internet using an Ethernet cable?

Your mac tries to determine your location based on nearby wifi networks. If you have wifi turned off, it can’t do that. So if you are using Ethernet, you still need to have wifi turned on.

Choose a place within the same timezone

Only out of interest, using this GeoLocation website

Just how accurate does it show your actual physical location ?

In my case, within about 10 meters accurate