If you call youself a web developer then you should know these things

Question

//Basic
1. HTML/CSS
2. Basic Tools
-Text Editor: Notepad++ | Atom.io
-Image Editing: Photoshop | GIMP
-FTP/SSH Tool: Filezilla, Putty
3. Javascript
-JSON
-JQuery
4. Web hosting
-Hostgator, InMotion, etc
-Learn Cpanel basics

//Advanced
5. HTML/CSS/Javascript Frameworks
-Twitter Bootstrap | MUI; Angular 2
6. PHP | Node.js | Ruby on Rails | Python
7. Databases
-MySQL | PostgreSQL
8. GIT
9. SSH & Basic Command line
10. HTTPS / SSL

Answer 1

It's not about basic or advanced level. If you are front-end developer then, html/css, javascript, jquery, bootstrap and so on.
if you are back-end then, php/python/ruby, databases, git, linux/unix, frameworks and so on

Answer 2

I prefer being both,
since front end web development is crowded,

back end knowledge is an added advantage.