That's a basic feature of every operating system: You can select text, copy it into the clipboard and paste it in another place. In your case that would be the URL of the newly created segment you will find when you open this segment in the browser.

As Jan_Mantau said, on the web browser, the best way is just to copy the URL from the address bar and paste that into a message to your friend.  If you can open the segment on a mobile device, just look for the little box with an "up" arrow on the top right.  Click on that and it should give you a button to "share segment".  Click on that and then choose how you want to share it to your friend.