WooCommerce B2B Store Upgrade Assistance

My B2B store, www.norwegiantrend.no, is running on WooCommerce and has reached the point where several extensions refuse to update. I want the entire setup—theme, design, and all plugins—brought up to current standards so I can handle routine edits, replacements, and upgrades myself with minimal outside help. Key needs • Refresh the theme and overall design to something fast, modern, and easy for me to tweak. • Audit every existing plugin, replace any that are no longer supported, and configure fresh, well-maintained alternatives. • Recommend new themes and plugins that fit a B2B catalog, multilingual pricing, and smooth checkout. (I have no fixed favorites and welcome your suggestions.) • Make sure everything stays fully compatible with the latest WooCommerce and WordPress core versions. • Leave me with clear documentation or a quick video walkthrough so I can confidently manage future updates on my own. Please outline how you would approach the audit, migration, and testing phases, roughly how long you expect each step to take, and your total price or milestone breakdown. Screenshots or brief examples of similar WooCommerce rebuilds you’ve handled will help me decide quickly. I don't have much idea what a website like this costs. When customers are done shopping, they click on Request invoice. I hope you understand what I mean. I would like an online store that is just as simple as the one I have now—this is because I want to change images and text frequently.