Hi Cioff1,
The taxi fare is between 25 and 30 euros to from Malaga airport to Fuengirola, depending on which end you are staying.
The train from the airport to Fuengirola runs every 30 mins from about 6.am until 11 pm, and the fare to Fuengirola is about 1.65 euros each.
Sorry I can't help with the taxi fare from Fuengirola to Calahonda , but experience tells me to warn you to, tell your friends to be sure to negociate a reasonable fare before they get in the taxi, We were charged 25 euros from the train station to Mijas Golf three years ago!!
The bus station is just across the road from the train station in Fuengirola and they could possibly get a bus to Calahonda (we've not yet tried it), but then depending on where your apartment is situated they may have to then change again to a local bus to get near to your apartment.