Answer 1

I know to use Html and Css
just write the pattern of html
after learning it on Sololearning
and save the file ans name.html
or name.css and for JavaScript
name.js

Answer 2

the most common for java is intellij and eclipse you can find them by googling... for html css and js i find visual code fron microsoft (not visual studio) quite usefull because it has a bunch of usefull plugins for preview etc

Answer 3

Some (better) recommendations:

Java: NetBeans (that's the IDE made by Oracle)
HTML and CSS: Adobe Dreamweaver CC. If you can't afford it, you can edit the files in Notepad++ and open them with your browser.