First thought: If you know who/what group is hosting the party, you might ask them what kind of music is intended -- slow paced music and modern fast doesn't necessarily mean much. Ask in terms of dance: Are they playing Swing music, or what?
If that doesn't work or isn't an option, I'd try to find an instructor (studio, school, universaity, youth club, whatever) and concentrate on just one or two dances. For slow music, you generally have the choice between (American) bolero or what I call Foxxy, though I believe it is called a variety of other things as well (a very slow fox trot, to the rhythm of Slow, slow, sway, sway). Foxxy is going to be the easier for you to learn, I expect. For pop music, your best all-around choice is probably swing. You can it to almost anything but a waltz.
*Argentine* tango is another option, as it can literally be danced to anything, but if you've never danced before, it may not be the best choice to learn with.
If you're really wanting to dance well for this girl, be prepared for a lot of lessons and a lot of work in the two months you have....
Good luck, have fun.
R
