In Microsoft office software if you press alt, menu items appear with a keyboard shortcut. Is this possible in Blender?
In this instance I was trying to select several edge loops with a combination of keys.
If you press the space bar you get a search tool where you could search the name of the required operation and it show the shorcut of it (if it has a shortcut)
Forementioned Searh command menu is the easyiest way if you know the command name. But if you don't you need to try opening every common dropdown menu look for you command to see if it has a hotkey. For you particular question about edge loops you first need to select at least one edge in every edge loop you want to select while being in edge selection mode(which can be toogle by Ctrl+Tab then 2) , then the default hotkey would be Ctrl+e then p. You can check other hotkeys by opening other commond menus in mesh mode like Ctrl+e, Ctrl+f, Ctrl+v and W and by clicking View,Select,Add,Mesh buttons in bottom left corner of 3d window.