In reply to Kentvilla:
> Yes I think I will need to try different shoes on as there are a few different types. Plus they are quite expensive so don't want to rush in and buy the first pair I see.
Yup. You should explain to the shop staff that you're looking for your first pair of climbing shoes, and ask to try on suitable beginner's shoes. Then it's a question of trying lots on and finding which ones suit your feet.
Because climbing shoes are meant to fit more tightly than regular shoes (your feet shouldn't be able to slip about inside them), it's vital that they fit your particular foot shape.
> So is there a big difference between climbing on rock and sandstone?
As sprinfall2008's explained, sandstone is a type of rock. The southern sandstone (the sandstone in the area round Tunbridge Wells) is especially fragile, much more so than normal sandstone, so there are these special rules for what kind of climbing is allowed on it.
The kind of climbing you'll have done is "top-roping", where you have a rope going up from the person climbing to an anchor at the top and then down to the belayer at the bottom. So if the climber falls off, they just dangle where they are.
In most places (other than the southern sandstone), you also have "lead climbing", where the rope runs from the climber straight down to the belayer at the bottom, and the climber has to protect themselves as they go by clipping the rope either into bolts that have been pre-placed in the rock (sport climbing) or removable gear they place in cracks in the rock themselves (trad climbing). Some areas have bolts and are for sport climbing, some don't and are trad-only.
If you fall off while lead climbing, you can fall some distance (depending on how far above your last bolt or gear placement you are).
And in most trad climbing areas, you don't have nice convenient bolts at the top of the crag, so if you want to top-rope, you have to be able to build an anchor yourself using trad gear.
So if you get into climbing and decide you want to climb in other areas as well as the southern sandstone, you'll need to learn some additional skills.