CakePHP with Homestead
SSH into your Homestead VM.
Edit /etc/nginx/sites-available/your-site.app and add /webroot to the line that looks like: root "/home/vagrant/your-site"; so that it looks like root "/home/vagrant/your-site/webroot";
Restart nginx with: sudo service nginx restart
Your should find your CakePHP pages can find their static content.
I don't know much about homestead, other than it is a vagrant box. I would suggest using a box that was tailored for cakephp:
https://github.com/FriendsOfCake/vagrant-chef
This is an article on how to get that set up correctly:
http://josediazgonzalez.com/2014/12/02/designing-a-store-application-in-cakephp/