All home owners are liable to pay the basura tax (rubbish) every six months and you should have already received notification and/or a bill.
If you have not received any notification/bill, you will need to collect one at the Nerja Tax Office, Patronato de Recaudación in calle Axarquia 3, opposite the junction of calle San Miguel and avenida Castilla Perez, and take it to your bank for payment.
The deadline for payment is January 5th 2015.