Why does your hompage button take you to a random product page and not your home page?
Instead of having all products and a drop down have those drop downs as main items in your header.
Each of your products needs a well written product description not crap imported from aliexpress.
Remove the dynamic checkout from your product pages
Change the add to cart button to a brighter color.
I would consider hiring someone to help you with further optimization help. You can get someone on upwork or fiverr for a good price.