Learn how to cut, copy, and paste text on your Android device with these steps.

Tap and hold your finger on the text box you are copying text from for about 2 seconds until a menu appears at the top of the screen and the text becomes highlighted.
Drag the selection to highlight the exact text you wish to work with.
Select the “Cut” or “Copy” icon located at the upper-right part of the screen.
Navigate to where you want to paste the text.
Tap and hold the text field for 2 seconds, then tap “Paste“.

Why doesn’t the cut, copy, paste feature work for me?

Not all apps support copying and pasting text.

How do I copy text from the Facebook app?

The Facebook app does not allow copying or cutting. For a workaround, you can bring up Facebook in a web browser and cut and copy from there. - @EconomeiQ