This depends on the size of the paddock, if it's more of a run attached to a stall then something like pea gravel is a commonly used material for them. But Sand or grass is better. If the paddock is any larger than 12 feet by 32 feet you need either grass or sand.
any kind,
Hell No.. what kind of question is that?
sand and gravel
Gravel
Tar or gravel
Gravel
It's not about what kind of horse you get, but how experienced the horse is. If you're not a beginner, but you've never had a horse before, your best chances of keeping one for a long enough time would be to get a well trained horse that's laid back, but will willingly work for you.
I don't know what kind of price range you have, but I saw a horse with a bright pink halter
It depends on what kind of horses coat your horse has all year round. If it has a thick coat then it would be fine in a weed-free paddock. If your horse has a smooth, fine coat it would probably need some sort of sturdy shelter against the cold. If your horse is an 'outside' horse, it would need a winter cover. It would also need some trees for shelter. It needs to have a fence and a gate. If you have a 'inside' horse you will need the sturdy shelter, a heavy winter cover and basic stable things. Hayley
sedimentary rock
The answer is Mineral
probably some kind of Stock Horse or Quarter Horse.