Most phones don't give you access to the clip board. It generally operates similar to a computer, where you have to long press inside a text entry box and select to paste it. If this is something you want to save for future reference, then paste it into a note taking app or similar.
Some phones do give you the option to view the clipboard. How to access it may vary based on the phone. For example, on my LG V20, I long press a text box similar to if I were to use the paste function, but it'll also give me a "clip tray" option. Selecting this gives me a pop-up of the last 20 items that were in the clipboard. It isn't like a note app, and old texts stored on it will be deleted as new texts are copied (unless I manually lock them).