Hugo page not found

Starting out with hugo I create an empty site for example with this template

Initially, it displays fine. but as soon as I stop and then restart the generator I only receive error 404 for the served files.

I discovered that the problem is the URL:

baseurl = "" < accepted by hugo, but not by gh-pages
baseurl = "" < working for gh-pages but not for hugo

How can I combine the URLs into a single working solution?
–> a http://localhost:1313/geoheil/ works locally but stilly why cant I accsess the regular domain ?

As far as I know the first URL should be working.

But when I try to use it on github - this is the error for the template mentioned above:
Refused to load the font 'data:font/woff;base64,d09GRgABAAAAAJd6ABIAAAABdegAAAAAAACWIAAAAVoAAAKDAAAAA…SYUnjpYfcSDw49uhYFPVe8dHZcYGS7Cfk4MMJ7zwjznvGw3PMA2Oo6+tf/wpSdPlSR/ADe7uPx' because it violates the following Content Security Policy directive: "default-src 'none'". Note that 'font-src' was not explicitly set, so 'default-src' is used as a fallback.

wrong URL / wrong name of repo

I had geoheil
instead of