Get familiar with a few basic chords that fit into the Spanish playing sound. Two important chords are A minor and E minor. These two chords are excellent starting chords to help you work on a simple Spanish sounding guitar pattern. Other chords you'll learn later on are E major, A major, F major, and B. You can purchase a chord dictionary from a music store or find one online free of charge (see resources).
Play the E minor chord and A minor to familiarize yourself with the sounds. For the E minor chord, place your two middle fingers on the second fret of your guitar neck on the A and D strings and play all of the strings at once with this chord shape, leaving the low E string open. For an A minor, place your index finger on the first fret of the second string (the B string), your ring finger on the second fret of the third string (the G string), and your middle finger on the second fret of the D string. These are the easiest chords to make and the best to begin playing a simple Spanish rhythm. Refer to your chord book regularly to ensure you form the chords correctly.
Strum the E minor chord, then play each individual string by itself without taking your fingers off the E minor chord shape. Play the strings from the thickest to the thinnest, then immediately switch to the A minor and play the same pattern. You'll hear the Spanish sound in these two chords. You won't use a pick for Spanish guitar. Use your fingers to pick single notes and all four fingers to strum. The best method is to bend your fingers and sweep them across the strings for a down strum or drag them over the strings for strumming up.
Strum the E minor chord three times quickly, with the first strum going down the strings, away from you, the second coming up, and the third strum down again. Let the third strum ring out for several seconds so it is noticeably longer than the first two strums, then repeat with the A minor chord. Continue to play this pattern back and forth until you are accustomed to it.
Combine the two patterns and experiment with the rhythm you used to play the chords. You can alternate your right hand rhythm to achieve the Spanish rhythm sound in a number of ways. Try picking notes inside the chords separately as filler when you shift between the chords. The sound will be there. It takes practice, but soon you will be able to combine these two chords with others to play simple Spanish rhythms on guitar.