SEO On Page Error need to fix

Currently have issues on Google Search Console I need to fix:
- Improving desktop CLS, FCP and TTFB
- Improving mobile LCP, FCP and TTFB
- repair merchant listing issues (issues are minimal 6/14 products)

Google Organic Search results:
-Assist with getting correct images and text displayed in our organic search results.

Google Shopping Ads campaign
-Assist with getting our adverts onto first page of google results for shopping.