Important WordPress Issues !!!!!!!!!

My first query is that can i use an image gallery along with wordpress on same site……or does wordpress support an image gallery or some sort of plugin…….

Secondly i’ve installed wordpress under say http://example.com

so if someone goes to http://example.com/wp-config.php he can get the wp-config file…….

how to stop this ???
i read the hiding wordpress files tutorial but it makes no sense to me……
Is there another plugin for that too or some kinda plugin ???

Plz help me…………..