Can't Access Admin & Links aren't working

When trying to access my admin page, it takes me to this error:

Warning: Invalid argument supplied for foreach() in /home/content/22/8516022/html/wp-content/plugins/share-rail/share-rail.php on line 77

Warning: Cannot modify header information – headers already sent by (output started at /home/content/22/8516022/html/wp-content/plugins/share-rail/share-rail.php:77) in /home/content/22/8516022/html/wp-includes/pluggable.php on line 876

I am new to wordpress, I did not make this website, and I have no idea how to fix it. I know that the site is hosted by godaddy.com but it doesn’t seem to be a host error. I already cleared the cache and cookies. I have no idea what the plug ins are or how to fix them. I’m afraid to re download wordpress because I don’t know how to save our website and I can’t lose our information.

Any help (in as basic language as possible as I’m not that good with computers) would help greatly.

Thank you.