I learned the basics in maybe a day almost 20 years ago now. I could make a page template with PHP and style that in maybe a day. This was back when IE6 was dominate, I don't think Firebug was even a thing.

At that time I was a novice, didn't know what a debugger was (I printed everything out the the console / page) and didn't know what an IDE was (I think I was using Notepad++). I managed this feat by following the tutorial.

The biggest problem I had was that I couldn't understand why centre, and colour didn't work. Once I realised that I had to spell everything in American English, that problem quickly went away.