Just open the windows search box (found on the taskbar, near the start menu, if not using the metro interface) and type remote desktop. The app will apear right on top of the list and you will be able to activate it. Good luck!
I really don't know, I never used the microsoft remote desktop.
May I ask why aren't you using a much better and free program (for home use, at least), to remote access a windows computer from an android or other windows device, like TeamViewer?
Remote Desktop is used to control other's PC and the remote PC will be locked. But if you use Remote Assistance, the one in front of the remote PC can see what's happening on his or her PC. This post is about the conparison between thwm. Hope it can help you. Remote Assistance VS Remote Desktop: Which One Should I Choose?