User profile in front-end

You need to do 2 different things to achieve this.

URL Structure:

Getting the URL in your desired format: http://website.com/user/username

By default, user’s archive URL is something like this http://website.com/author/username

There is a plugin to change author slug, install this plugin and set the slug to user

Plugin: https://wordpress.org/plugins/rename-author-slug/

[Note: I’m the author of this plugin]

Displaying info:

Customize your author.php file in theme directory and show specific information.

In this file, you can get any of information a user has.

To get a user’s display-name, simply use <?php the_author_meta('display_name' ); ?>

Or to get his first name, use <?php the_author_meta('first_name' ); ?>