How will we use javascript ,css and html in one page

Answer 1

You need to learn:
https://www.sololearn.com/Course/HTML/?ref=app
And please see:
https://www.sololearn.com/Discuss/1316935/?ref=app
Before posting a question.
Tag for link the js:
<script src="java script file name">
Tag for link the css:
<style src="css file name">
You can use this tags in head and body tags.

Answer 2

//On this lesson methods has been briefed nicely,
https://www.sololearn.com/learn/CSS/1079/
https://www.sololearn.com/learn/JavaScript/1124/