D madd9 Chord

Play each string individually first, each note should ring clearly. Then try strumming.

For barre chords, use your index finger to press down all strings at one fret (works as a movable capo), while your other fingers form the shape. This can be hard, but you'll get there!

When you move to barre versions, use your index finger as a movable capo. It takes time - start with just the barre and add the other fingers one by one.