Of course you can start free. Use Wordpress. It is far
more versatile than anything else.
Before you start, consider what you are going to write about. Don't say "everything". That is a surefire way to create writer's block. No lie. Limits help with creativity.
Write up a list of topics. This is freeform brainstorming. Let's say you want to write about music. Is that jazz, hip hop, country, acid rock, something else? Is it about concerts you've attended, or history, or songs you write? See where I am going with this? Specificity is your friend.
Consider the look and feel of the blog. Can you draw, design, or take pictures? Then you own all of that intellectual property.
If you can't, then either use public domain images (NASA has a bunch) or buy images. Check licenses on free images very carefully, to be sure you're not stealing anyone's work. I'm not kidding.
Don't blog more than maybe 3 times per week. Create a schedule (say, Monday, Thursday, and Saturday) and stick with it. Wordpress has a scheduling feature-- use it. And if you're inspired one day, write a few posts and schedule them into the future.
Standard blog length should be at least 900 or so words.
Tweet links to your blog or post the links on your Facebook wall. Don't expect to draw a large audience. There's nothing wrong with that. Most blogs don't have huge audiences.
I have been blogging for over 11 years and have a Master's in Interactive Media . This is how I do it, and how I was taught.