hello apple, the default homepage url is about:home - but what you're describing already sound like the current firefox homepage. the world is just temporarily there in celebration of the new firefox launch and for promoting the https://webwewant.mozilla.org campaign...

FireFox will not accept the about:home url and reverts to the new default with the world map.

The access buttons at the bottom of the page are still there. For now, don't worry about it.

^ Other than the issue that the start up time is delayed sometimes, depending upon the load on the Mozilla servers, when Firefox tries to load that image from the Mozilla servers.