First allow all permissions for your project folder (let say it's called laravel), for the storage subfolder and its logs subsubfolder and for the vendor subfolder (laravel/storage, laravel/storage/logs and laravel/vendor).
Then check if your have .env file - if not you can run:
$ mv .env.example .env
to rename your build-in .env.example to the needed .env.
Otherwise turn on the debug mode - open .env and set
APP_DEBUG=true
and open laravel/config/app.php and change
'debug' => env('APP_DEBUG', false),
to
'debug' => env('APP_DEBUG', true),
so you can find out what is the reason for your error.