Display a custom name when the user has no name settle in his account

I’m creating a code that shows the First Name for logged in users, using a shortcode, but I noticed that if the user has no name settle, it will display a blank space. How can I set a custom name to show up instead of the blank space? Something like this “Hi >No Name<, please settle your name in your account.”

Between functions.php (theme), widgets, and plugins, which is loaded first?

Customer asks if a specific carousel plugin he uses can be widgetized. That means I should create a widget inside functions.php which calls the plugin’s function. That means that the plugin’s code has to be loaded first so that the function be available to WordPress when the functions.php file is loaded, right? Would that work?