I get an error whenever I try to update my wordpress version or install a plugin

Hello. I’ve been trying to get my wordpress updated because I’m running a really old version, but whenever I try to install a plugin to backup my information (I can’t do it the manual way because I’m kind of technologically impaired) an error pops up:

Fatal error: Cannot redeclare pclziputilpathreduction() (previously declared in /home/content/i/n/t/intlwota/html/aitakatta/wp-content/plugins/wordpress-automatic-upgrade/lib/pclzip.lib.php:5421) in /home/content/i/n/t/intlwota/html/aitakatta/wp-admin/includes/class-pclzip.php on line 5498

I really don’t know what to do, and I don’t want to be stuck using this super old version of WordPress and being unable to install any plugins, especially because I want to backup my information. Any help would be greatly appreciated.