Difficult to answer without knowing what you want to do. However, firstly remember that Puerto is the original resort of Tenerife so loads of family attractions and also night-life for younger visitors. I would say that Lora Park is a must see no matter what. Originally parrots performing but now includes marvellous sea-lions, dolphins and many more - beware of sitting at front at sea-lion show, you will get wet but there is a warning because obviously kids like it. There are loads of things to see on excursions - Dragon Tree reputed to be 1,000 years old, lovely villages. It is good to see the South of The Island - Las Americas etc. - to see the difference.
I am sure you will have an ejoyable time, no matter what ages and circumstances.