Site problems

My site works perfectly offline on the localhost, but when online my jquery doesn’t seem to work at all. ajaxload, ajax bla bla and bla do not even try to work.

Bla bla is a really bad explanation of the problem, provide URL at least.

When trying to sign in from this page: www.lumna.epizy.com/pages/home.php, it redirects to: www.lumna.epizy.com/php_processes/process_sign.php. Here it gives a “no such file or directory” error.

lumnar said:
When trying to sign in from this page: www.lumna.epizy.com/pages/home.php, it redirects to: www.lumna.epizy.com/php_processes/process_sign.php. Here it gives a "no such file or directory" error.
Can you provide full error text? (example: Error: No such file or directory on /htdocs/myfolder/script.js on line 133)

There is no error text. Just that.

no such file or directory
I don't see any error like that. All Javascript URLs respond with Javascript code, looking in the Network tab in my browser.

Also, where do you see this exactly? Is it an error on your page? Do you see it in the browser console? What exactly is "it" giving such an error?

It is an error on my page, and I sincerely don’t know what “it” is. All I know is everything is working perfectly on my localhost, but here, not exactly.

lumnar said:
It is an error on my page, and I sincerely don't know what "it" is. All I know is everything is working perfectly on my localhost, but here, not exactly.
I don't see that error, but come to think of it, "No such file or directory" can also be caused by using the wrong database hostname.

On your own computer, the web server and database server run on the same system, which is why you can use the database hostname localhost. 

On our systems, the websites and databases run on separate servers, so "localhost" doesn't work. You need to find your database hostname in the control panel and use that in your code instead.