Laravel - How to take first name and last name from separate fields and store them in name column in db?

So I used php artisan make:auth in my project and I am building on top of that. Problem is it has only "name" field and not "firstName" and "lastName" field. Where do I configure those options? I want to take the input from first name and last name and concatenate them with a space between them, then store them as name in my db. Where is the place to do that? Where do I configure my options like if I want to add an address or phone number for my user? I researched a lot and I am really confused with all those traits so please could someone give me some advice on how to proceed with user authentication?