HTTP 500 Internal Server Error, pages not loading or found

Hi,

I don’t know what to do and am very inexperienced with WordPress. I made a website using WP. The link is: https://sandbarsportsgrill.com

The site was finished last week and my co-worker tried to make the site live. Somehow he did something and messed it up. What he told me he did was this:

1) created new folder for all old files
2) tried to transfer all files in ‘site’ folder to the root folder

Well, that got messed up so we backed up WP site and database. Then we reinstalled WP and re-uploaded wp-content, wp-admin, wp-include via FTP. (Should we have done that?)

Now our issue is getting the pages to show-up/work. If you click on a link in the nav, it is supposed to take you to a page but I get this 500 Internal Service Error. In the pages when I click ‘Live Previews’ I can’t even see the page either and get the same error.

Notes: We never touched any of the code since last week and it was working fine last week so we dont think it is a php programming file problem but we’re not sure? The pages are also not working in any theme, including default theme. Our site is hosted on GoDaddy. I dont have access to server error log.

Can someone help me figure out what to do/what else to check out? I’m really nervous about messing this all up even more.