Removing featured image and using pages/ categories

Hello, I am a complete beginner at Worpress and I am finding a couple obstacles really difficult to get past in the process of creating my blog. The current things I am finding difficult to resolve are… Removing the featured image.

I want to have a featured image on pages that display my blog. I am using Genesis Framework as my theme and the child theme is called SingleBox. This is the theme I am using. http://bylt.me/get/singlebox/demo/
All I want is to have my blog set up so I can post to it. Basically, so it looks how that demo site looks. However I am getting stuck. When previewing my first post the featured image appears at the top of my blog post. I don’t want it to appear in the post at all. Only as a thumbnail when in the feed of the page/ category I assign it to.

I have tried publishing the post unfinished to try alter a few things and see how it will look when published on the site. However 1) the featured image is at the top of the post, and 2) there is no summary of the post at all. It’s just the entire post sitting on the category I set it to. For example on the demo you can see a picture (Thumbnail), a small description and then read more. On my page there is no summary, it’s just the whole post.

I am not sure if this is to do with me not understanding how to set my page up. First I tried making the pages I want to set different posts to. For my blog it is Film, Tech, Fitness & Health and Journal. I then discovered when creating a post you don’t set them to pages, you set them to categories. So I removed all the pages and made my menu full of the same titles but as categories. I wanted a home page where all my posts show, as well as the individual categories holding just the one type of posts.

As I mentioned I am completely new, I am really struggling learning because most forums haven’t a completely different level on complexity and level of savvy people. I am completely new, I know next to nothing and if anyone could try an help me I would really appreciate it. Thank you – Luke