Shopify Website Coding Tutorial

I just had a website created for my online fashion boutique. I need to hire someone who is an EXPERT in navigating the SHOPIFY RETINA theme to explain to me how to change fonts, sizes, add text to pictures, etc. I need to use the ANYDESK platform and have someone show me where to insert the coding and what it needs to say. I know absolutely nothing about coding so I need someone very knowledgeable, patient, and well versed in English to make this as easy as possible to understand through Anydesk. I would prefer to have a list of codes already made up that I can just insert into the right places that would enable me to add text over pictures, change the fonts, sizes, add text to the banner, etc. For someone experienced, I think this should take no more than an hour or two to explain.