Hiya!

Child theme - not necessary. Its only suggested if you make your own modifications.

Directions? In the help area (the bee icon) you may find a start-up tutorial if you scroll down a bit. I'm still building the help area.

The first thing I would say is go to the network panel of that screen and do that first. Follow the breadcrumbs and make sure you complete that. its hugely important for your SEO.

Another thing after you go through some of the help-startup stuff is you can always post questions here.

Awesome to see you involved I hope you have fun.

Wordpress admin - you see a bee and ladybug...click the bee and there are your main symbiostock administration tabs...those should be fairly self-explanatory but most things are done there. Plus there are "help" links for most options.