To get to the camp from Lisbon airport, you will need to take the metro from the airport to the station Campo Grande. There you will find a big bus station with the same name. From the station, you need to take a bus to Ericeira Terminal. When in Ericeira, you can take an Uber or a taxi to the camp, which takes about 5 minutes. You can also walk to the camp, which will take around 30 min.