How to play a harmonica with 32 holes
The 32-hole harmonica is a form of tremolo harmonica. While typical harmonicas have one horizontal row of holes, tremolo harmonicas have two, creating 16 vertical pairs of holes. Each pair represents one note, and both holes are played simultaneously.
The reeds are tuned slightly off so that when they are played together, a tremolo or "wobbling" sound is generated. Furthermore, while typical harmonicas have two notes per hole--one sounded by expelling breath, and one by drawing breath--the pairs of holes on tremolo harmonicas are sounded by either one or the other.
Hold your tremolo harmonica with both hands. As a beginner, don't worry about holding it in a special way; for now, it's enough to simply hold each end, thumbs underneath. Don't block any holes.
Wet your lips. Place your mouth on the rows of holes--remember to play the holes in vertical pairs--and blow. Pucker your lips and attempt to sound only one pair of holes at a time. Don't be discouraged--it takes practice to shape your lips correctly.
Explore your harmonica. Don't worry about theory or technicality. Practice until you're familiar with your instrument's layout, and have a good idea of which holes are sounded by exhaling and which are sounded by inhaling.
Try to play a song you know from memory. Traditional songs like "Mary Had a Little Lamb" are a good place to start. This will be very slow going at first, but be patient; find each note, no matter how long it takes.
Practice, practice, practice. Experiment with different mouth shapes and learn how variations affect sound.