Keen on a second hand board currently advertised on Seabreeze, it is a carbon board, as new, but at a really good price compared to a new es or wood equivalent of the same board. If I'm only beginner/ intermediate should I stay away from carbon boards?

No carbon board are not just for pros. Some of the pro's like Koster prefer the wood boards for jumping as they are a little more forgiving when jumping high. Carbon are generally lighter and stiffer.

My advice is try and buy what you dream about and you will be stoked riding it. Carbon or not.

Like most questions... it depends. If it is a carbon slalom board, then no. If it is a carbon freeride board or freestyle wave board the in some cases it may be stronger. It should definitely be lighter. It will feel crisper or stiffer than a wood board which is not to everyone's taste. Construction quality varies between brands just to add complexity

As paddymac said it depends on the style of board- most carbons tend to be the slalom/race models which isn't ideal. Carbon pretty much you just need to be careful with the nose and careful not to bang your heels or knees down on board when getting up (but this really applies to any board), in return you get a crisper, improved responsiveness & sometimes a harder ride.

Beginner/intermediate myself. After some experience with damaging both wood and carbon boards there is an advantage to non wood boards.

Wood swells in the presence of water - a consideration if you can't get off the water soon enough with a damaged board. The swelling can complicate the repair.

I really like carbon boards. They are responsive and light.
I had a JP freestyle 99L you could lift with your pinky. Fantastic board.
And another F2 FSW 115L at 7kg...amazing boards.

Problem, they translate the bumps to the knees and hips directly, so you need thick foot pads..or youth...

So the advice is, intermediate or advanced, get a carbon board if you can with tick pads otherwise , get a wood or ...

It depends.
Carbon is just a material. Sturdy boards are good for beginners and pros alike, and are easier to make using carbon. Which does not mean that all carbon boards are sturdy (not at all!). Stiff and light boards are mostly good for pros or expert riders, and not so good for beginners or for anyone that likes to keep his ankles healthy; and often carbon is used to obtain such kind of boards.
In some cases, as carbon is often used in 'extreme' designs, a fault in designing may result in faulty boards. Those Starboard iSonics from a few years ago with UD carbon decks are a perfect example.