Google have a blog for you included in your own Gmail account, please read the initial procedure on Create a blog , the very first step of the Blogger Help page
You can manage your blog both on desktop and mobile.
BTW, having a blog is not strictly necessary, as you already know, to be invited to Connect Live
There’s really 1 good tip @BudiFXW : make sure you have good content. Of course this is a very general statement, which can (and will) be interpreted very differently by different people. My personal interpretation: well structured and clearly written content that might be interesting to a least a number of people.