Shopify UX & Imagery Refresh

.My current Shopify store is functional but is not giving visitors the polished, intuitive feel I know it can deliver. The priority is user experience: cleaner navigation, an uncluttered layout and a checkout flow that feels effortless on desktop and mobile alike.
Visually, I want the site to work harder for the brand. I am a distributor with access to high-resolution product photos and accompanying specifications, so there is plenty of material available to replace generic stock imagery. Thoughtful image placement, consistent sizing and appropriate image optimization/compression to keep load times fast will be important.
I am looking for a theme refresh or bespoke tweaks, whichever best fits, implemented directly in Shopify using Liquid, HTML/CSS and lightweight JavaScript only where necessary. SEO-friendly alt tags and schema should remain intact. The end result should be a professional storefront that naturally guides shoppers to the right products and keeps them engaged through purchase.
Additional Priorities
The site must be easy for me to manage myself after completion. I need to be able to add or remove products, change pricing, update photos and descriptions, create promotions and change homepage content without needing a developer.
Create professional, conversion-focused product pages with product photos, pricing, key features, specifications, compatibility or use cases, installation information, FAQs and prominent Add to Cart / Buy Now buttons.
Organize products into logical collections so customers can quickly determine which GPS or tracking product is right for them.
Use clear calls to action throughout the site, including Shop Now, Request Information, Contact Us and Dealer / Business Pricing where appropriate.
Make the site useful for both individual buyers and commercial/dealer customers, including an easy way for businesses interested in multiple units to request volume pricing.
Build the site so new products and product categories can be added in the future without redesigning the website.
Optimize for mobile-first use, page speed, image compression, Google search/SEO and a straightforward checkout experience.
Use Shopify's native theme editor, sections, collections and product templates whenever possible rather than hard-coding content that I cannot easily change myself.
Do not install paid Shopify apps or create new recurring software expenses without my approval.
At completion, all theme customizations, images, settings and other work must be transferred to and remain under my Shopify account and control.
Provide a short walk-through or training session showing me how to change products, prices, images, homepage sections, promotions and other routine site content.
Primary Goal
The finished True North GPS website should not only look modern and professional; it should be designed to convert visitors into customers while remaining simple for me to update and operate independently through Shopify.