Welcome here. I also just started blogging, but is is definitely a great journey.

Welcome to hashnode, I have literally just started my journey here as well (I write over on DEV.to primarily)

To answer your question, I would say it isn't important as such (you can be a great programmer without blogging), but it can certainly accelerate your career and open up a lot of opportunities!

If you want to be a technical writer you need to:

• write regularly
• get familiar with how to format posts well
• learn to research well and link to related information well
• practice grammar, punctuation etc.

If you want to write as a developer for job advancement / community:

• Write about what you enjoy
• Have a buffer of articles (release on a consistent schedule, so have a few articles in reserve for if you get busy)
• Interact with the articles of others
• Work on building up your social media at the same time (I didn't do this and regret it now)

And finally the benefits of blogging as a developer:

• Public learning is a great way to get feedback (the negative feedback when you get something wrong is possibly even more valuable than the positive feedback as it is like having an angry metnor! 🤣)
• Your "soft skills" will improve automatically and make you better at communicating, skills which can really help in a developer role.
• You end up referencing your own work - the amount of times I find my own answer when I am googling a problem is surprising!
• It promotes discipline - you need to post consistently (how often is up to how much time you have), so you have to be consistent in your writing.
• It lets you make connections - I have some great online friends because of content creation, it is a great way to meet like minded people (and people with different opinions)

Keep writing, you will enjoy it I am almost certain!