How to change what the post creation page looks like?

Is there a way (plugin, or something else) to set it where there is a drop down on the “New Post” page that allows you to choose a post type and the fields change allowing you to filter what content you are putting into a post without confusing a user by having 20 different custom fields on the “New Post” page.

Also, is there a plugin or other that can make custom fields with different value types (textarea, list, file upload, etc)?

This was asked over and over:

• Add custom field automatically to custom page types
• Redesigning Custom Post Type “Add
  New” page

and if you are not into coding the you can use plugins like

• Simple fields
• More Fields
• Verve Meta Boxes

hope this helps