Create user in users table and insert data into second table with one form in Laravel Relationships
It's a correct way to do it like this.
Few suggestions:

Add validation before creating user. You don't want to fail on save for duplicate user email. For better UX if you can it's a good idea to do it even before form submit (with ajax request when email field is changed).

If your app has more user related things like user profile, user control panel I will suggest you to auto login user after form submit. Just before redirect() add Auth::login($user)