My first Twitter advert. What do I need to know?

I need to splash £50-£100 on Twitter ads. It's my first time. I'm only targetting people that uses Shopify, BigCommerce, Spree Commerce and maybe WooCommerce as that's what my app is built for. Since the app is not ready and the ad is basically Q&A, what should the ad contains? Screen grabs? Should I use my Twitter account or the business account with me being mentioned in it? Any tips at all? My Facebook ad got rejected as the link pointed to the Google docs directly. Maybe I should have pointed it directly to the app landing? 🤷🏽‍♂️