Development environment

Hi,

It would be great to have a development environment integrated with my WP dashboard, where I can develop a new replacement for the current website alongside it. I want to develop and change things in terms of structure, themes, tags, design, pages, everything in stealth mode, while updating and running the current site as well. When the new one is ready, I would like to simply replace the current one with the new one, e.g. by clicking on a button in a development environment.

I have seen some suggestions about setting up development environments (mostly local), but they seem quite technical, quite a bit of work and the how-to suggestions largely focused on Windows, while I am on a Mac (and not a developer, programmer, etc).

I have found the Dev-and-staging environment, but it has not been updated for a looong time, has not been tested with current WP versions and I have been running into trouble installing it. (In fact, all my other plugins currently have gone missing while installing the plugin. Still working to get that resolved..) So that does not seem to be very attractive.

Does anyone know whether such a plugin / solution / option is available somehow?

Thanks!