I have 2 plumbing questions in reference to shower and "rough in" plumbing?

Q#1

Pop off the cap in the center of the shower knob or handle with a flat head screwdriver to expose a screw underneath,

Remove the screw with a screwdriver then pull off the knob or handle to locate the no-scald adjustment underneath.

Move the setting dial to adjust the flow of hot water that passes through the shower head. Each adjustment stop clicks at the new setting. Turn the dial clockwise to allow more hot water to pass through the valve.

Replace the knob or handle and secure it with the screw.

Snap the plastic cap back onto the knob or handle.

Q#2

I do not understand what hose you are going to install but you have to cut those caps off to install any thing to the pipe. Hence why they are sticking out of the wall so far.

The water connections are probably CPVC and the drain could be CVPC or PVC. You have to cut the caps off below the ends (they are glued on) and then glue on fittings that will connect with whatever fixtures you are connecting. You should actually have shut off valves be the first thing you attach to the pipes so you can turn off the water any time there is a problem and while you are working on the installation. The water may be connected to these pipes now so you had better shut off the main water valve to the house and put a bucket under them before you cut them off. Once you have cut these off, though, you're committed. Unless there is a downstream cut-off valve where you can isolate the lines, you will not be able to turn the water service on to the house again until you have attached proper shut off valves to the two water rough-ins. The drain pipe should be capped now too -- it is a potential source of dangerous sewer gas sitting open like that now. At least stuff a rag in it until you get the sink or vanity installed.

Honestly, you don't seem to know enough about plumbing to be able to do this installation on your own. There is quite a bit more to it than just attaching something randomly to the rough-in pipes. Do you know about p-traps and j-traps to block sewer gas and about anti-hammering fittings? It is also critical that you know exactly what size and material the rough-ins are so you get the right fittings and adhesives - a plumber could tell right away but I doubt you could.

If you are dead set on doing this yourself, at least get a book from the building center on basic plumbing installations and read it carefully. For your shower problem, you need to get a copy of the instruction book for the shower control and refer to it instead of using trial and error. If you don't have the manual, you could probably download a copy on line at the manufacturers web site or go to a Plumbing Supply dealer and ask them -- bring any information you can find as to the brand name and model and a clear photo of the control unit so they can determine what it is.

PS If you do this work yourself and something goes wrong, your homeowners insurer could deny payment on any damage claim that results. In the long run it is usually better to leave plumbing and wiring to the professionals. Some municipalities even forbid homeowners from doing such modifications and almost all of them require you to have such work inspected even if you do it yourself.

the scald feature is inside the dial... usually just something blocking the knob from turning to far in the direction. take it apart and remove it.

the rough in pipe cap is probably glued on... cut it off... don't know why you're trying to put a hose down the drain anyway but whatever.

edit: oh, the cap is on the water supply line and not the drain? in that case, 1) why isn't that copper? 2) you'll need to put a shut off valve on each of those before you hook anything up for a sink.