You can use laravel mix to compile your all css and js if you have node installed, for that you have to put your css and js in resources/assets folder.
You have to install node dependencies by running npm install in your laravel folder.
For compiling your js and css you can use
mix.js(['resources/assets/js/app.js'], 'public/js');
mix.styles([
'resources/assets/css/style.css',
'resources/assets/css/style1.css'
], 'public/css/all.css');
in webpack.mix.js file, it will compile all your css and js to public folder into single css/js file.
you can use npm run dev to compile your files or npm run watch to add watcher when your js/css files change
more reference here