This really depends on your timetable and how much time you have to dedicate to your dancing. Most instructors agree that two weekly classes of an hour and a half each are ideal: there’s no point in rushing it at the beginning.
Make sure that you listen to your body and don’t force it to do anything you’re not comfortable with. Don’t give up just because you find something difficult. In any case, if you like dancing then going to classes shouldn’t be a drag. How fast you progress depends on all the different factors already explained.
Perseverance and hard work will obviously pay off, but a positive attitude will help you get there faster. If you’re determined and try your best you’ll learn fast. If you’ve done other sports in the past and you’re in good shape you’ll also make good progress.
Everyone finds it difficult at first, especially if you haven’t done any exercise in a while. Hang in there – you’ll soon find you’ve come on in leaps and bounds.
The initial period of very fast progress will soon wear off, though, and you might feel as if you’re not getting anywhere. Don’t worry: you’ve simply reached the plateau, the point at which you’ll make steady but sure progress.