Bilingual WordPress Redesign With SEO

My current WordPress business site (about five pages) needs a complete visual and technical refresh directly on the live install, with no content freeze if possible. I want a modern, sleek look that loads fast, scores well on Core Web Vitals, and follows a mobile-first approach. Every section—hero banners, text blocks, and image galleries—should be set up in a visual builder so I can tweak copy or swap images myself later.

Key requirements
• Bilingual navigation: English and French served through automatic language detection, falling back to a manual switcher if the user prefers.
• Editable announcement bar at the top for promos or urgent notices.
• Lightweight theme or custom child theme, avoiding bulky plugins.
• Fully responsive layouts tested on major devices and browsers.
• On-page SEO: keyword research, meta tags, schema where relevant, and clean URL structure.
• Build directly on the existing site; handle backups and a staging copy so there’s no downtime.

Deliverables
1. Five redesigned, speed-optimised pages published on the live domain.
2. Global header, footer, and announcement bar editable from the customiser or page builder.
3. Dual-language setup with automatic detection working across all pages.
4. Basic SEO report outlining keywords used, meta descriptions, and performance scores.
5. Short handover guide (PDF or video) showing me how to update text, images, and announcements.

Acceptance criteria
• Desktop PageSpeed ≥ 90, Mobile ≥ 80.
• Language switch fires correctly on first visit.
• All content areas editable without code.
• No broken links or mixed-language slugs.

Please keep plugin choices lean (e.g., Elementor, WPML/Polylang, Rank Math, or similar) and make sure everything remains easy for a non-developer to manage once you’re done.