ibanez rg 120 action

hey whats up?...ya i have a ibanez rg 120..and when i play..something like sweet child o mine (gnr)...there is a buzzing...i'm wondering if its me..they way i'm playing or .the action is set to high on my guitar..its got a standard tremlo....so if it is the action how do i adjust it to get a lower action..one thing i have noticed also that the strings are higher abover the fret..down by the 12-24 frets..and is closer to the frets 1-12....what is it?

aight thnks man...ya..i use ernie ball super slinkeys..so i think there is a lil gauge diff in em..but not a whole lot.....but thnks man...