The scroll wheel on your mouse is probably a functional middle button.
On Linux, you can usually left-click-drag-release to highlight some text, move your mouse cursor to a new location (in any window), and middle-click once to paste the text you highlighted there. No explicit keyboard or right-click copy and paste required.
If you ever use the middle mouse button to open links in a new tab, you should disable this "feature" because it is a security vulnerability which allows for grabbing the clipboard content.
On Linux, you can usually left-click-drag-release to highlight some text, move your mouse cursor to a new location (in any window), and middle-click once to paste the text you highlighted there. No explicit keyboard or right-click copy and paste required.