Upon arrival, I recommend buying public transport cards, which can be loaded with individual rides, but especially a day ticket, which will pay off for traveling in the city. The card can only be bought at metro stations and costs 0.50 Eur. It is valid for 24 hours from the first validation and can be used in the city on the metro, trams, cable cars, buses, and elevators. The fare can be further topped up on the card.

Payment for fares is also possible by credit card directly in the metro/tram, but you can only buy individual rides with it, and each person must have their own credit card; it is not possible to buy a ticket for, for example, two people on one credit card.

You will get acquainted with the center of Lisbon. You will walk through the main square, explore the Bairro Alto or Baixa-Chiado district. You will move around the city center on foot and by tram. First, you will visit one of the viewpoints - Santa Catarina, walk past the famous café to the elevator designed by a student of Gustav Eiffel. You will walk through the Baixa-Chiado shopping district and end the day in the square by the Tagus River.

Lisbon is said to be located on seven hills. There are viewpoints on many peaks - miradouro in Portuguese. Today, you will walk through the Mouradia district or the oldest district of Lisbon, Alfama, and in the afternoon you will go to the other side to the city of Almada, where the statue of Christ-Cristo Rei is located.  

For today, I recommend charging a card for so-called zapping for about 10 Euros, you will use it for tram, boat across the river and bus in Alamda. You will need the fare in the afternoon. In the morning, the narrow streets of Lisbon are best seen on foot.