It is very easy to set up a blog, I have one on my website which is provided by Weebly and I have a personal one and one for my publishing business on blogspot which, I believe, is part of Google.
Setting up is easy. Knowing what and when to post is the difficult part. Do you want to blog about something specific, life in general or are you supporting a particular cause?
The next thing is to post regularly to keep people interested. Something I fail miserably at (posting regularly that is, hopefully people are interested!). This takes up time and eats into other things you should be doing. Also, you need to have something to say, otherwise why blog?
Finally, you need to let people know you have posted something, usually through whatever social media you use, be that Facebook, Twitter or any of the other platforms now available.
Hope this helps.