Changing the way posts look like

Hello, i’am trying to achieve 2 things.
First of all, when im creating to a new post, lets say “my first post” as the title and some content, so I get this page as the url of the post: mysitename.com/my-first-post, and it contains the title and the content. What i want to do, is to change the way it displays the post, for example, make it display the title twice or something, basicly i want to change the way a post is looked(not the styling but the actual way of displayment).

And the second thing, that is kind of a continue of the first, I also have a custom post type called shop_items, and I would also like to change the way it is displayed, for example make it also display the custom fields. How can i do this?

Thanks in advance,
Gabi.