Why should you care about writing
Why start a blog?
People may not read everything you write, and that is fine. You do not need everyone as your audience. If you write for everyone, the post often helps no one.
A better starting point is a problem you spent hours solving. Maybe you searched through documentation, tried several fixes, and finally found what worked. If you write down the solution, or even the steps that did not work, you help the next person facing the same issue. That person is your real audience.
How to start
You do not need a complex setup to publish useful notes. For many personal blogs and documentation sites, a static site is enough. It serves content as files, which can be simpler to host and maintain than a database-backed platform.
Writing from real experience also adds useful information to the web. Clear notes about real problems, edge cases, and fixes can help other people find answers faster.