I learned WordPress on my own. It took me more than a month to get comfortable with all the options.
In the beginning, it will be a little daunting, not knowing how to give a name to your WordPress, to add a page or post or add an image or adding a plugin, etc. Everything seems confusing.
There are some main things which every website would need. If you learn those, you can confidently say you know WordPress to some extent.
1] Setting up the name of the website
2] Adding a logo
3] Adding pages
4] Adding posts with text and images
5] Creating menus with pages and links
6] Adding footer credits
7] Adding home page and enabling the blogging page
8] Adding a theme and activating it
9] Installing new plugins etc
Once you know to do these things, you can say you know how to use WordPress.
The next phase of learning WordPress starts when you want to set up a premium theme. You should know how to use all the options of a premium theme like changing colors, selecting different fonts, increasing fonts. Using predefined templates etc
After that comes the stage where you build a site from scratch using a page builder like elementor or Divi.
Here you are the designer. You are the one who decides the number of pages, the color, the things which will go into the page, etc
Overall to reach this level it would take 4 to 6 months.
If I have to reiterate the timeline in a simple way
Basic WordPress Learning – 1 month
Theme setup and customization – 1 month
Building websites from scratch – 2 to 3 months
Overall if you give 4 to 6 months it would be possible to become good at WordPress