how can i install node.js or what other app can i use to create my own code for javascript and html

Answer 1

https://nodejs.org/en/ here is documentation and installation for node js have a look

Answer 2

i have downloaded it but i dont know how to install is it because im using a chromebook

Answer 3

https://medium.com/@jacoboakley/web-development-with-a-chromebook-installing-nodejs-4e358b82a31b follow this guide