GitHub Pages Questions, not sure what to do.

[TheAngryProle]

For reasons I don't want to go into, I am wanting to transfer my website that's in development through Otterwiki that's hosted on another persons server to Github pages.

I've only started learning Markdown/ Syntax and a little CSS, but I'm still not sure how to make the GitHub pages.

• I'm not sure if GitHub pages accepts Markdown when using Otterwiki? Are they separate?
• I'm working on a project that requires frequent updating. Is there a secondary software I can use to write and test Markdown/Syntax code in bulk before transferring it to GitHub?
• If I have a project with dozens of pages, does GitHub require individual static site for each? 
• Can I make the project and continue editing it until I'm ready to go live? Can I edit content after it's live?
• Can I add SEO? 

Are there guides for absolute beginners?