The melody of Marry You by Bruno Mars runs 402 notes across 64 bars, 3:23 long in Bb at 144 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? Marry You chords and lyrics.