SEO UK Magento homeware e-commerce SEO audit / healthcheck and google ranking / conversion improvements & internet marketing

I am looking for an seo audit, website health check, advice and help improving Google rankings for my UK base Magento homeware e-commerce store. I am open to onsite SEO, marketing, social media and high-quality link building. WHITEHAT only, anything remotely BLACKHAT will be ignored. I have my own onsite auditing scanner/software, not looking for an automated scan and pdf report and a backlink link campaign from free accounts. I will only consider bids from bidders who have actually read this description, so please start your bid proposal text with the word "ecommerce". Issue: Steady decline in organic Google traffic and resulting sale conversions from google traffic and are asking for ideas on how to and assistance with improving Google rankings back to or beyond where they were in the past with the aim to increase converions/sales. Concerns to start with: I have found an increase in websites hotlinking my images and backlinking to me from spammy domains and the domain hasn't had any strong do follow backlinks in a few years. I have also moved our website to full https and want to confirm the redirects are set up for the best seo results. I have a target keyword profile and I am considering starting a second website selling the same products but under a different set of targetted keywords. These are just what I am aware of, please some less than perfect onsite SEO which I am working on correcting. I may provide url on request via freelancer messenger.