You can find all sorts of steps here:
memory.loc.gov/ammem/diht...videos.html

Mid-nineteenth century is what you're looking for!

But the best way is to ask a Fezziwigger to teach you! :)

And come to dances, particularly
peers.org/events.html
and
www.gaskellball.com/next.html

For those without easy access to the website or to Peers and/or Gaskells...

The majority of the dances are simple rotary waltzes. Modern box waltz doesn't move enough, and Viennaese isn't exactly correct, but if you can learn (know) that, rotary is easy. Polkas are polkas. The Mazurka that's generally done is referred to as a Waltz-Mazurka, and alternates a rotary waltz step and a mazurka step. Schottisches are generally done in the much easier open position - there exists a closed position, but unless you're good, it's easy for the man to end up an octave higher than he started.

With that terminology, many dance studios may be able to help you. Note that most of them are teaching modern competition ballroom, which tends to be very different than what gets danced socially, so make sure you be specific. And I did find one Fred Astaire Studio a few years ago that was willing to teach polka, so they do exist.

Then there are the special dances: Congress of Vienna, Bohemian National Polka, Lancer's Quadrille, Sir Roger de Coverly and a couple of others. You probably won't be able to find studios to teach those.

Bohemian National Polka steps are here: socialdance.stanford.edu/syllabi/BNP.htm

you also live remarkably close to stanfurd and richard powers' occasional classes. you can show up to friday night waltz to learn most of the dances (as well as a heavy emphasis on the modern cross step waltz, which has been popularized and spread mostly by richard himself).

the best way to improve is to dance with a few skilled follows who can help you out and give you pointers. classes help to give you the basics to get going on the floor. luckily for you, palo alto is simply swimming with skilled dancers.