recommendations for buenos aires

hi guys! my boyfriend and i (22 years old) will be going to buenos aires for a few days (dec 29-31), any recommendations for food (i love steak & only eat steak), and activities (love anything outdoors, not a big party person but would love to do some dancinggg), thank you!! also is there a fake beach in argentina? i love the beach, vintage shops, culture, dance and gooood steak! it looks like all the good steak restaurants are booked??