I first built a website over 15 years ago and simply learnt ‘on the run’. The website was for our family small business so I started small, made the first things I learnt ’work’ then moved on to the next task. Slowly but surely.
Learning ‘HTML’ was my first hurdle - it’s the underlying code of any website and should be the first thing you learn if your goal is to build a website.
‘CSS’ was my next challenge - and on it went from there - buying a domain name, setting up a hosting account and then linking the 2 together.
Today, those processes are second nature to me and building websites has evolved some much over the last 15 years that keeping up with technology is quite simply hard work!
So - start small, start slow and learn the basics. Probably applies to anything in life I guess.
'Sitepoint' has some great books to get you started. https://tinyurl.com/y7xupj2s