Start out in G. The 3 chords of "Every Rose" can be open chords, which means your fingering will be different for each one. G is composed with your middle finger on low G (third fret on E string), index finger on B (second fret on A string) and your pinkie and ring finger on the top 2 strings at the third fret.
Now alternate between G and C. The transition is easy, just move your index-and-middle-finger combination up 1 string.
Use G and C in an alternating rhythm along with your lyrics to play both the verse and the chorus.
Find the few places where the chord goes to D. One is in the first verse with the lyrics: "Though I tried not to hurt you" where this bar is played with a D chord, with fingers on the second frets on fourth and sixth strings, and the third fret of the fifth string. Another D is in the chorus at "Every cowboy..." where the D is in the second of four chords.
Watch out for the bridge. The bridge of the song has a couple of extra chords, the sequence goes like this: E minor, D, C and back to G. That happens twice in the bridge. Figure that out, and you're done; you can play this soulful glam-rock dirge on your own front porch or in the local coffee house.