If you want to create and control your online brand that allows you to communicate to a global audience then you can do it for free with sites like WordPress.com, Tumblr and Blogger.com.
You can even setup a Facebook page as some have done.
Free is good but it comes with some downsides. The challenge is that the providers who own those platforms have certain features and functions that limits your flexibility and control. You are operating under their terms and conditions and you also don’t know if they will be around next year.
If you want to lay a strong foundation that will be sustainable into the future then you need to create your own WordPress blog with your domain that is self hosted. This will provide you with the ultimate in flexibility and control.
I made the mistake of using WordPress.com when starting and a year later I had to go through the pain of transferring it.