I'm being taught to step left and back as the lead for cha cha. On this site, the lead starts right and then forward. On another site the lead is shown to start left and back as I'm being taught.

As the follower in Samba, I'm being taught to start with left foot going forward first and then bringing the right foot to touch along side . On this site and on the other dance site I frequent, the follower starts with the right foot going forward first; then brings the left foot to touch beside the right!

Am I being taught incorrectly, or is there a difference in style, such as club style vs ballroom style...or perhaps a difference in american and international?

Latina. One is called a Natural Basic Movement. The other is called a Reverse Basic Movement. Both are correct. It is neccessary to be able to do both. It seems that the Natural Basic Movement in the USA is more prevalent. The Samba is without a doubt the most difficult of all the dances any style to do correctly. Good Luck.

Serendipidy, thank you for clarifying! I've been confused by this for a long time.
Samba is my favorite dance. I've learned just enough, however, to realize that it won't come easily or quickly...probably never progressing beyond intermediate. I enjoy it though, regardless of level.