Did it also install the Modules in the ACP?
If you are new to this stuff then you might not know about Automod
. I apologize if you are not new.
Also, again presuming you are new, consider creating a second version of your site using a separate database. If you do your playing there it doesn't matter if you break the site because your users are unaffected. Once you have tried out a new modification and find that it works "as advertised" and is what you want on your site, it is easy to upgrade your "real" site.
Personally I wouldn't try to premod phpbb, I am still a child when it comes to this stuff although I am learning every day; often becoming badly bruised in the process.