If you have a look at class CL_GUI_FRONTEND_SERVICES, mentioned already by Jörg, you will find all the methods there to do what you need for your purposes. You can also click on a method and then click on where-used to see how other programs and classes are calling these methods and then figure things out from there yourself. There are even sometimes demo programs for some of these methods.
It seems also you are new here. These forums are a great help to me and many others, and certainly if you need help or get stuck you can ask questions here but you have to do some investigation yourself and you should not expect to be spoon-fed here. Don’t post screen-shots of your hand-written notes and ask for this to be converted to code!