Text Editor not great

What do you mean? The TEXT Editor or the VISUAL editor???

I mean the text editor

No option to underline the text or change font size or font type

Is it basic deliberatly? Do I need to install an advanced editor?

Thanks for your reply

You are probably mixing two things together. If you open any page or post to edit, you can chose between two “editing modes” “Visual” and “HTML” (see 11 at picture in following link). Visual can do all the requested(fonts usually only if your theme support this). HTML editor is one where you can edit code on your own.

See that tutorial:
https://www.justinparks.com/wordpress-posts-15-things-beginner-need-to-know-when-creating-wordpress-posts/

What kybernaut said ??