Apple Mac Pro - reload OS for a beginner's new start? I'm a recent refugee from Windows and new to all Apple basics. I've bought a secondhand post-2013 Mac Pro and I've discovered (unsurprisingly) that I don't have Administrator's rights to load software. Looking at Forums it looks like quite a task to gain it. As my machine doesn't have any 3rd party programs or data on it, it seems to me that the easiest solution would be to reload High Sierra. Is that a good idea and can I do that without those Admin rights?
Yah, do it. Restart holding CommandR. Choose Internet Recovery and reinstall the operating system.

The only thing that will slow you down is the speed of your internet connection.