can not preview in browser

Some time ago i moved my web site and having never done so the new setup was painfull with all the little things I needed to do but I got there eventually.
So the web site is in a working condition,released and being used.
However if I want to preview the web site localy by hitting F12 the page cann't find the server and therefore can't be displayed that was fine for the time being but now that I need to do some changes technically I would have to do the changes and release the web site out on the interent in order to see my changes,obviously I can't do that,because previewing in it locally helps go through errors.

I was told to look at the properties of IIS on my server which I have done but I don't see anything there.
Then i was trying to find my local IP by running winipcfg but then I get an error that the winipcfg file or some of its components can't be found,coudn't really find much on the internet about it,so now I am stuck and need some kind of a suggestion.

Hopefully somebody has one.

regards