I’m sorry, but if you delete a file, the file is deleted. There is no Trash folder to recover the file after deletion, and we also do not make any backups of free hosting accounts you could recover the file from.
If you have a copy of the file yourself, or some way to obtain it, then please reupload it from there. If that’s not an option, then I’m sorry to say that file is lost.
You can’t permanently corrupt an account by deleting a file. And moving to a new account won’t make any files that are missing from your website reappear.
There is no such thing as a “http access” file. The closest thing I can think of is the htdocs folder of your domain. But if that’s missing, you can just recreate it yourself. No need to get a completely new hosting account for that, with all the trouble and downtime it brings.
usually a webserver will display the directory contents when there is no index file but on infinityfree the directory listing feature is disabled by default so you will get a 403 access denied error
this message just means that directory listings are disabled you still have full access to your website
if you recreate your index file everything will be fine