Which Operating System should I use?

I recommend using a Windows Machine because most of the Virtual Reality Sets are only supported by Windows. There are quite a few issues with Macs, Unity3D & Virtual Reality. You can though use the Simulator of the Software on a Macbook for testing purposes.

You can use a Macbook for Oculus Quest, but the file transfer will be more difficult and slower.

On Windows, Oculus Quest will automatically appear as a drive on your computer. On Mac, you’ll need to install Android File Transfer to successfully transfer files between your Oculus Quest and computer. On Chromebook/Chrome OS, you’ll need to use the Files app to access your Oculus Quest headset. (Source: https://support.oculus.com/855551644803876/)