Normally if you access public folder it will directly hit index.php file automatically.
But in your case most probably your .htaccess file is not working so that you are required to add index.php in URL to run project.
Open your .htaccess file under public folder of your project and add some random text at the top and save your file.
Now try to access your project.
If you are getting 500 Internal server error after adding a random text in .htaccess file.
It means it is working.
If you are still able to access public path of project which means .htaccess it is not working yet.
so you need to enable it in case of linux.
Open your apache2.conf file and Allow overwrite All.
Options Indexes FollowSymLinks
Require all granted
Now also you need to run two below commands for enabling mod rewrite rule.
service apache2 restart
For windows you need to make changes for apache config file as same we have done above for linux.