Hi ptah101
This relates to the tmp folder in the root directory of your site, kindly check if this folder exists or not, if not, create it.
Then make sure that you set the correct permissions for it: by default, it's '755' for folder
About php.ini file, cPanel in some hostings have option to change it. If you don't have permission, you can ask your host for help to change it.
To find the path of 'php.ini' file, you go to Backend >> Global Configuration >> PHP information tab: Configuration File (php.ini) Path