Help with customising an online store template

Hi there, I'm opening an online store using ShopFlow ([login to view URL]). I want to customise some elements from the templates provided. They give you full access to the Code editor - which has the Cloud storage, HTML and CSS code available to change. I'd like to change elements such as: 1. Background colour 2. Adding social media links for each product so customers can share (Facebook/ Pinterest), and also social media links for the store - Instagram/ Facebook/ Pinterest (always visible in the footer, or at the side of the site) 3. Columns (from 2 to 3) that are responsive 4. Adding 2 x more pages to the navigation. 5. General once over of any other elements to tidy up the theme - such as T&C's link and copyright on the footer, main logo centered in the header, links that have a hover colour etc.. This is a good example of where I'd like to take the template, which the current themes don't have the functionality mentioned above. [login to view URL] I have some HTML and CSS experience - but this time I'd like a professional I can rely on that is quick and efficient and can guide on the process too.