Shopify store integration

The store is at a satisfactory level. The store has its own domain, the homepage is almost ready and the product categories are ready. The changes I need are the following. Minor interventions in the header, footer and body to make it look more professional. Addition of products that I will give away (15-20). Set up a product page as you see fit. Interface with PayPal and stripe which I will create. In general, a clean-up that I don't have time to do due to professional obligations.. In general, to make a functional store according to the standards of the market.