The easiest and safest way on concrete is to build two ramps connecting the two pools. usually build them 8' on both sides of the rails. Then up the center you would run your 4x4 posts which will be the supports for the rail. Frame out the shape of the rail you want off the 4x4 posts then cut the top of the 4x4's off. Throw trex on top and you are done.
As for the wall ride I would connect it to your ramps. you want around a 30 degree angle to the wall ride. Otherwise it is to steep. Use some Bathroom shower sheeting. Comes in a 4x8 sheet at home depot. Glue it on with some good glue. Your set.