I'm confusing my horse! English riders! I need help!?

I understand a few cues, but My TB mare knows Dressage and I am a western rider, I have no idea what I am doing! The other day I was riding, and she started to leg yeild on me! After that, She was preforming flying lead changes. I had no idea what im doing, and I do NOT want to frustrate her! I need simple warnings or cues so I do not confuse her. Also, How do I ask her to gallop? I know not to beat her with my feet or kick, I know to sqeeze with my lower calves.