It really depends on your goals. If you want to learn ballroom dancing, than rumba, waltz, swing and cha-cha are popular dances to start with. It depends a lot on what your objecvtives are. if it is ballroom dancing, the studio should have a recommended sequence of learning, starting with what they feel is best.
it seems strange that the studio did not make suggestions. We did not have an answer to that question, so they gave us theirs. Which worked out well.