I read once Every good blog post should have a goal, and every writer, content marketer, blogger should understand the role of it, and I totally disagree with this.
You can start your blog just to collect your thoughts, to write about your path learning a new language, or about something new that your found in your career field.
In my case, I'm writing this blog to practice my English writing skill, talk about Python and the whole ecosystem around it, talk about anything that I think is valuable for me or others to know more, and also turn this blog to be like a Brag Document the ideas posted here will have actually be more useful to me to help me reflect on themes in my work, what’s important to me, what I’m learning, and what I’d like to be doing differently.
I'm a voracious reader of technical and financial blogs, all of these blogs are written by people like you and me, so why not start to write one? Start your blog today, like I'm doing now!