E-Comm Social Media Marketing for Coffee

The Black Lion Coffee is a company dedicated to selling organic and fair trade certified coffee. We want to highlight the qualities of our product. We want to drive users to our website and convert them to buy on our Amazon page. We are a new company so we decided to use Facebook and Instagram to reach potential buyers. We are working on getting a blog set-up to do Google SEO because we understand its important to reach more users. However, we want to start with FB and Insta. Our Coffee: The Black Lion Coffee sells 100% pure organic Yirgacheffee premium coffee. We sell 1lb (16oz) bags on Amazon Our coffee is 100% pure; certified Fair-Trade-Certified and Organic To summarize: We want social media marketing on Facebook and Instagram. We want to re-target ads to get to our website or Amazon page to buy --> Is it better to drive users to our site or directly to our Amazon page? Questions: How much should we allocate for ad buys for a startup? What's a realistic conversion rate per 1000 hits on our landing page? What's a realistic time frame to get users/followers on our handles What experience do you have with Facebook and Instagram marketing?