Many of the latin dances are based on 'cha cha', and it's easy.
The beat is usually "one, two, one, two, one, two" in other words, 2/4 time (if you know music. If not, 1-2-1-2 is okay)
So the beat is simple 1,2,1,2. To dance cha cha, start with your left foot like you're walking forward. On the next beat, follow with your right foot, just as if you were walking. Then when the next music beat comes, put your left foot down, then your right then your left again quickly and within two beats as if you were counting like this:
1,2,(1-2-3),1,2,(1-2-3),1,2,(1-2-3) It's like saying "One, two, (cha-cha-cha), one, two, (cha-cha-cha)..." then instead of putting your right foot down again, you move it forward like you were walking forward again, and repeat the dance step. Right foot, foot, then right-left-right, then move your left foot forward so the dance is like this:
Left, right (cha cha cha) Right, left (cha cha cha) and so on.
It sounds more difficult than it is.
I'm editing to add that bp1974 is correct to LEAD. And that the cha cha is best suited for songs that aren't too fast. If it's fast, just move. If it's a semi-slow song and you want to hold her, then I recommend cha cha. You will get her wet.