For musical people this song is easy.  Its a basic I IV V pattern

For people who arent theory nerds its G C D


Intro
E)--------------------------------------
B)---0----0--------------0-------------
G)--3----3------5-4-----3------------
D)-2----2------4-------2---------------
A)-----3------5-------------------------
E)3-------------------------------------

Verse
E)---------------------------------------
B)---------------------------------------
G)-------55--77--55----------------------
D)---55--55--77--55----------------------
A)---55--33--55--33----------------------
E)---33----------------------------------


Chorus is the same as the verse