Don’t start building straight away. Instead, use something like ahrefs to determine if there is demand for your idea. After this, build a simple landing page and drive traffic to the site.
Start as a side project or make sure you have the financial runway to pay your bills for at least a year. Do things that don’t scale: do everything that it takes to get your first customers and worry about scaling processes later.
Your first product will most probably fail, make sure to fail early and often! It’s good to inform yourself, but don’t get paralyzed in tutorial/researching hell… Start out and learn by doing, and get more experience.
Start out with content pages. It’s easy and there is not a lot of technical knowledge needed. It’s also an excellent way to get into “making money online”.
The first dollar I earned independently by myself was through Famewall.io which was a SaaS to collect & manage testimonials. I got paid $11.99 for the first time for something I created by myself 🙂