The melody of Heartbreak Girl by 5 Seconds of Summer runs 476 notes across 72 bars, 3:19 long in Eb at 166 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? Heartbreak Girl chords and lyrics.