To start a blog: start a blog. The point of entry has never been easier. Do it.
Two paragraphs? Sure! That is enough.
Treat it like a slip box, as learned in How to Take Smart Notes. Deciding taxonomies up front is a fool’s errand. Writing, free form, is all it takes.
Even titles can be too much. It’s the problem of CSS. It requires giving things names up front, before you know what the thing is.
This is where writing is so important! Play with ideas about where you’re going and what you’re building. Use writing to think before taking action. It’s cheap! You can imagine realities before expending the energy to realize them. Maybe it’s not even a reality you want to pursue.
Action begets action. Ideation begets ideation. Both are necessary. And you need to know which phase of the project you are in.