Flight
House Or Rental
The venue of the events on Saturday and Sunday is in the San Telmo neighborhood of Buenos Aires. This list should give you some options if you'd prefer to stay in San Telmo. You can also choose to stay in another neighborhood like Recoleta (upscale), Puerto Madero (very new, but less to do), Palermo (lots to do, but further away) and Uber or Taxi to the events.
Hotel
This is the hotel most guests will be staying at. If you are not staying here, but want to travel with other guests to events, like Welcome Cocktails, meet them here and you can take an Uber or cab together.
Travel Note
from ezeiza (the airport). after you go through customs, you will exit through a corridor where you'll be bombarded with offers for transport, including car rentals. ignore all of these. keep walking and you'll exit to the main airport area, where you'll see a lot of people arranged in a make-shift semicircle, waiting for their loved ones. if you look right, you'll see a starbucks —and if you want some coffee, this is your best airport choice. kitty-corner to the american coffee house, you'll see a counter that reads, "taxi oficial ezeiza". this is the transport you want. they will ask you where you're going and give you a rate (to the city, this will be ~50,000 pesos, or ~45usd w/ your visa card). after you pay, they'll hand you a receipt, shortly after which someone will come to pick you up, and take you to your car. you will hand the receipt to the driver, and they will take you to your destination. expect the trip to take somewhere between 45 and 60 minutes, depending on traffic. tipping is not expected, and as such it's typically appreciated, so feel free to do that if you have some paper money.
Travel Note
uber works really well & is preposterously inexpensive. you can pay w/ the card on your uber account, or you can select "cash", and pay as you're getting off the car, as you may with a regular taxi. keep in mind cars in argentina are typically smaller than the ones you're used to in the states. if you're willing to wait a few extra minutes, go for "comfort", which generally costs ~10% more, but are bigger & nicer cars.