Custom user pages and removing wp-admin pages for users

Hi, i like to make a website where when user logged in there they will have a settings page, and custom item post page which i will design and also a text editor will be needed.

I want users to login but dont want them to see the wp-admin area. So, the total idea is a full custom backend for the users.

Please let me know how i can i do this. The items will be posted now from the user backend not the wordpress backend. And what kinds of security matter i should be aware of.

If anything unclear let me know.