Dancing, casualties expected...

I really feel I go to a wrong course. The first half was terrible, then it was better, even pleasant, but still, I can't dance so it seems gradually worse and worse idea to go to this course :-(
We were learning a new variation in jive (we exchange position with a partner, the partner turns here and there). Then there was an open promenade in polka, this wasn't that difficult, but I didn't know (and do not even now) how to shift from the promenade to normal polka step (there is some spinning of the partner, that I didn't get). Then there were some funny steps in samba, just beginnings, we didn't apply it in dancing itself, and then we were told how to really dance samba (i.e. as a round dance). Last, in salsa, there was a turn for girls when exchanging places.
I don't know. I'll try practicing a little, though it's going to be hard, when I have virtually no one to practice. I'm used to finishing all the courses I once begin, but then, I'm also used to having at least some success. Not like in here. Dancing is fun, I just can't do it...