I haven't been to Paphos in over 2 years and I live in Cyprus.... I have to admit it's not my most favourite of places because for me, it's now too touristy and a lot of the tradition I found in my first years of visiting Cyprus in the mid 80's have long disappeared.
We live on the outskirts of Limassol on the edge of what is now a suburb but used to be a fairly large village where we have all we need without really having to leave it. I go into Limassol town every weekday to work but we rarely go into the tourist area except when we have family and friends on holiday. We go to our local restaurants which serve a mixture of Greek and International cuisine (depending where we go) and to our local beach at Curium not too far from where we live. We've been here for over 8 years and you start to adjust to being a "local" after about the first 2 years and certainly after 5 years!
So if you haven't already been to Paphos or if you have in the past, you may probably appreciate where I'm coming from...
However, in Paphos you will find all kinds of restaurants and places to eat. You can have a choice of English, Italian, Chinese, Cypriot meze and traditional dishes, Russian - you name it you can probably find it. Cyprus caters for all nationalities when it comes to food.
When you're out and about and if you fancy a quick snack you will see small catering units (like ice-cream vans) where they do some fab sandwiches. A Mixed sandwich will be a hot sandwich on a long roll/baguette and is usually filled with chicken, pork, cheese and possibly bacon with tomatoes and cucumber. Or my favourite is Halloumi Lountza (pronounced loondzah) which is grilled goats milk cheese (thats the Halloumi) with a smokey pork bacon type of meat. Again, served hot (zestoh).
However, this link to the Paphos area of Cyprus-Eating website will give you an idea of what food is on offer:
http://www.cyprus-eating.com/paphos-eating-out-guide
You can search by food type - eg "British" to get a list of restuarants and find something suitable near to where you are staying.
Tea For Two will give you a good choice of English style food with a homely feel about it. (A new one opened on the seafront and there used to be one on Tombs of the Kings road near the Pit Stop pub). Plus there's one in the old town which has a fantastic view over Chloraka bay. They could possibly be a good place to start off with to see how your son goes with it as the cafes don't have a totally foreign look about them. A lot depends on where you will be staying and if you have any form of transport as there are restaurants and bars along the front from the harbour and all along until you reach Yeroskipou end of town and again, loads from Tombs of the Kings road and out to Coral Bay.
I'm sure you will find something to suit. Enjoy!