The rules for copying from the command line are tricky. Old Windows made you right-click and select “Mark,” newer Windows selects directly, but how do you copy to your clipboard?
In old UNIXes, you’d simply select text to copy it, and just click where you want it to paste it. It was simple but a little tricky.
In modern Linuxes you can (usually) CTL-SHIFT-C to copy and CTL-SHIFT-V to paste in the terminal, or do the right-click thing.
Or you can try out a utility that makes it all easier like xclip: