Go to your tools & see if the commands are enabled, if not click on them in the tools Dropbox & then they should work. There may also be a cut & paste clipboard symbol up top left hand side to click on. it may be under edit if not tools. I'm not at my laptop so can't say for sure.
I don't know about enabling these two commands, but you could try the key stroke commands. Ctrl + C = copy. Ctrl + X = cut. Ctrl + V = paste. Sometimes these will work, even when a command for copy, cut, and paste are not seen. Hope this helps. Good luck and God bless.
You can try to restart your computer and see if it works. You also need to check and make sure that neither antivirus nor applications has been used to lock the copy/paste functions on your computer. You may contact a professional IT technician for more advice.