Introduce your horse to a variety of fences at home before expecting him to deal with different obstacles at shows. If your jumping facilities at home are limited, seek help from a suitably qualified instructor who has more extensive facilities. You may find individuals with a good selection of fences at home - or check whether your local show centre runs lessons with trainers. There are now many opportunities for riders to gain help and experience with their horses.
This is when two poles cross in the middle between two wings. This type of jump may be used on its own as a training fence - the shape is intended to encourage the horse towards the centre of the fence. However, some trainers don't like to use these for inexperienced horses at an early stage of their training. This is because punishing a young horse for not being straight can be detrimental to the horse. If your trainer is of this viewpoint he is likely to use small uprights for introducing the horse to jumping - then the onus is very much on the rider to produce straightness in the horse's approach and jump.
Cross poles can be used on their own or as the first element of a spread fence.
A simple, upright fence, with a pole placed in front of the fence at a distance equal to half the height of the fence eg a pole 12 inches away from a fence, which is 2 feet in height. The pole on the ground is there to help the horse gauge his take off point. These types of fences are useful for inexperienced horses, novice riders and are also used when training, for horses that need to become sharper with their forelegs.
These are introduced once your horse is jumping ascending verticals correctly. True verticals may be constructed using poles, planks, walls and gates and there is no ground line. The ideal take off point for these fences is approximately the same distance away from the fence as the height of the jump.
These fences can be quite challenging for the rider and the key is to keep the horse in a balanced canter with an even length of stride. You should wait for the fence to 'come to you' as trying to see a stride to fences like these often results in the rider over collecting the canter.
A triple bar is a good example of this type of fence. You need to ride these fences with an active, forward approach.
These are spread fences but they may be true (in which case they may look like a vertical on approach as the front and back rails are the same height) or ascending.