There is no vendor folder in laravel project. I download the laravel using composer create-project laravel/laravel. What problem?
Please delete your current laravel project and install new one. It might be a problem when downloading laravel project.
You can use alternate way instead of using composer. You can download laravel from github.
There may be some issues here. Have you ran composer global require "laravel/installer" before? And have you given a name, for example composer create-project laravel/laravel my_project?
The project (cd my_project) will be created in the folder where you run it. If the outcome is still not the way you expected, try composer clear-cache followed by composer create-project --prefer-dist laravel/laravel my_project so you bypass the cached packages.