Q: How do I archive a backup on a Windows computer?

Because those instructions are for Mac computers and Mac version of iTunes. You can locate your backup by looking for its location in this support document. Find and manage your iTunes backups - Apple Support  and make a copy of it and place it somewhere else. Otherwise, you will have to ask that question in the support you get for the public beta. Discussion of the beta on the public forum is a violation of the NDA.

You should get those directions as part of the instructions for the public beta test. Either way, you won't be able to discuss it on the public forum.

What Mac has a right click?

As far as I know, all of them. Use a mouse with more than one button, a two-fingered click on some mice & trackpads, or hold down the option key on the keyboard as you click.

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