Remarketing campaigns are used to show ads to people who have visited your website or used your app. These campaigns provide you with extra settings and reports specifically for reaching previous visitors and users.
What I will do ?
I will create the Remarketing lists, Generate the code to add it in the website, Review that code is added correctly or not, Create the Remarketing campaign Dynamice or Simple, Design the Automate Image Ads with AdWords.
Dynamic Remarketing is recommended only if You have ecommerce website and more than 20 Products.