There are two bus stations in both Albufeira and Lisbon. NB these would be called coaches in the UK, like National Express. You buy tickets before you get on, either at the website or at the ticket office.
In Lisbon, most go to Sete Rios, which is a 10 minute ride on the metro (underground) into the city centre. Oriente is much further out, near the airport.
There are five trains a day to Lisbon but the station here is nearly four miles from town.Edited: 19 January 2018, 16:23
Looking at the website, there are promotional tickets for E16 first class Albufeira to Lisboa. However, the regular price is E26,20 and, with a 50% seniors discount, these tickets would be less expensive. I'm thinking there isn't any point in buying in advance. Am I correct or missing something. Thanks.
Probably correct, because the tickets with an higher discount can already be sold out...