I was learning from my mobile i how to get notepad please help me

Answer 1

Go to you app store, example Google Play store

Install a text/ code editor app

Example: js run (javascript editor) app

Answer 2

Most of the note pads/text editors can open source code.
Or change the extension to .txt
i.e: "code.cpp" to "code.txt" then open it.
Hope it helps.