Most popular songs in 4/4 time can be played using just a few foundational patterns:
: Practice new patterns while muting the strings with your left hand. This lets you focus entirely on the rhythm without worrying about chord changes. Essential Strumming Patterns
: Your hand should move down on every beat (1, 2, 3, 4) and up on the "ands" (1 & 2 & 3 & 4). To create a rhythm, you simply miss the strings on purpose during certain motions while keeping your arm moving.
What are some good strumming patterns to practice? - Facebook
: Beginners often start with only downstrokes (D-D-D-D) to lock in the timing before adding upstrokes.