Method 1: Upload via WordPress Admin

1. Go to Appearance → Themes → Add New → Upload Theme
2. Choose the gratis.zip file
3. Click Install Now then Activate

Method 2: WP-CLI (Recommended)

wp theme install https://github.com/your-repo/gratis/archive/main.zip --activate

Method 3: FTP/SFTP

Upload the gratis/ folder to wp-content/themes/ and activate from wp-admin.

After Installation

Visit Appearance → Editor to start editing with Full Site Editing. Your first stop should be the Patterns tab in the block inserter.