Hello opto,
for the 1st question: you can use property nodes to display a certain number of elements of arrays. Wire the user input "no of values" to a property node "NumRows" of that array and you get this number of elements. (You can also adapt the window size to the array size by setting the apropriate property nodes of the vi [FP.Panelsize]). You should initialize this array with the desired number of values.
I don't understand your 2nd question. What do mean by moving from one menu to the next? Should Labview open a menu and "move" through it? Normally the user selects a menu item and you get his selection with "Get Menu Selection".
Best regards,
GerdW
Best regards,
GerdW

using LV2016/2019/2021 on Win10/11+cRIO, TestStand2016/2019