Hi Salmee. I'm just a beginner in CB too. Unfortunately the PHP mode is not something you can control unless you host your own sites.
Having SafeMode turned on for PHP, disallows file creation which is why people sometimes have trouble installing this (and other) components.
Best place to start would be to contact your host and ask them to turn php safemode off. There are other workarounds posted on this forum if you just search for "safe mode", but contacting your host would help in this instance and also for any other components you might want to install.
good luck.