Your comments

I'm being thrown a NGINX error -- that much being stated I'm almost certain. The issue standing is that my domain is not pointing to my Node app's port, therefor I'm not sure where it's pointing @ my server. Though, as explained prior, if I pop :3000 onto my domain and physically try to access this port, I'm directed to my node app without any problems.
Error logs are specified correctly, I've tried viewing them via nano and the Ajenti CP -- but they're completely empty, including the access log. Just in case I even chmoded the files and triggered the error again, no luck.
Config is okay as also shown on Ajenti's CP, as for the error logs - they're empty.
In more simplified context, Ajenti is running my node app flawlessly, NGINX is proxying to my domain no problem, but my app isn't accessible on port 80 of my domain.

So I have to physically request the port my app is running on, on my domain, to get the node app.

* ps * disregard my original statement about the index file

Thank you for replying so quickly, and I apologize for replying so late - I just got out of work. As for your first question, yes, Ajenti is running my application as intended ( I have forever installed for debugging, but it's not in use ).

Everything's working fine, but when I access my domain associated with my app, it just throws me a NGINX 502 error ( Bad Gateway ). That being stated, if I try and request my domain with the port my app is being hosted on ( 3000 ), I can access my node application without a hitch.

Regarding my error logs, they're completely empty.

It's not really much of an error, more of a configuration type issue.
*Updated* Checked the generated nginx config -- should be sending requests to port 3000, but it's not?
Note I can access my node app by visting www.mydomain.com:3000