The melody of I Miss Her by Jessie J runs 370 notes across 43 bars, 3:27 long in Gb at 80 beats per minute. The tab sits low on the neck, mostly under the fourth fret, one note at a time — no chords to barre and no strumming pattern to keep up with. A piano backing track plays the chords and bass underneath, so the line you are learning sounds like the record even at half speed.
Prefer to strum and sing it instead? I Miss Her chords and lyrics.