How exactly do I get Bistro Child Theme to work with my Sydney Pro?

Hello

I would like to build a site around the Bistro Theme but I have the licenses for all of the pro version of your Themes. Do I install Sydney pro First then add bistro as a Child Theme? And the demo content will also be loaded?

I’m not familiar using Child Themes so sorry if this is a dumb question lol

OK got the theme to work with Sydney but for some reason i can’t get it to work with Sydney Pro. Is this how its supposed to work?