Help fixing design issues and responsiveness of Wordpress site

I have an existing Wordpress website I developed myself. It is an e-commerce and subscription based business and need help fixing certain issues such as white space after homepage header, size of images etc on the homepage and unwanted header images on the product pages. I also need help to make the site more responsive on mobile in particular. There are other things I would like help with such as tagging product images in the shop, and SEO for the website overall including product pages. There may be other things that need fixing. Happy to hear from anyone who can take on all this type of work or just parts. My website is www.prettyandspice.co.uk There may be other issues you spot and could perhaps also help with design suggestions or update design and layout for better user experience.