There are a number of health centres (or ‘centros de salud’) in the centre but it is important that you go to the one that corresponds to your address. If you live in the historic centre, it is most likely that your affiliated centre is the one in the port on Avenida de Manuel Agustín Heredia, 36. It is located within walking distance of the Muelle Heredia bus station.
If you don’t live in the centre then you can consult your nearest health centre at this link.
You need to bring your NIE and social security number and your ‘tarjeta de salud’ (health card) with you. If this is your first time signing up with a doctor in Spain then they can issue you a number at reception. The card (which has a microchip and is used to collect prescriptions) will arrive in the post within four weeks. In the meantime, your number alone will suffice.
You can use the number to make (or alter and cancel) doctor’s appointments on the online portal.