No — this tool covers standard SEO/browser meta tags (title, description, robots, canonical, charset, viewport, theme-color). Use the dedicated Open Graph Tag Generator for social-sharing tags.
Not really — Google and most modern search engines ignore it. It's included here mainly for completeness and legacy tooling that might still check it.
Paste them inside your page's <head> section, and update your <html lang="..."> attribute as shown in the generated comment.