Flight
Newark and JFK airports both fly directly to Lisbon via TAP Air Portugal Airlines. If you are having trouble finding a flight you like, check out one way trips to/from Newark or JFK from your home airport and book a round trip ticket from Newark/JFK to Lisbon separately.
Hotel
This 4-star hotel is less than 5 minutes from the venue and will likely be the most convenient for your stay.
House Or Rental
Airbnb is another great option to stay in the area or to explore other nearby cities such as Sintra and Cascais. Average costs are about $60-$100 USD per night for various sized rentals.